Re: Trading resolution for depth of field
Not correct, if bad eyesight leads to a percieved COC larger than the generally defined COC, a larger deviation from the focal plane is needed to see a reduced sharpness, hence the percieved DOF is larger. JC OConnell wrote: no, they have less DOF since they see less in focus JC O'Connell hifis...@gate.net -Original Message- From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of Derby Chang Sent: Wednesday, April 08, 2009 5:43 PM To: Pentax-Discuss Mail List Subject: Re: Trading resolution for depth of field Jos from Holland wrote: Exactly! Thats why people with poor eyesight are lucky: they have a larger COC MARK! -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
On Tue, Apr 7, 2009 at 9:28 AM, David Savage ozsav...@gmail.com wrote: I know, I have added quite a few to the technically competent, but mediocre, pool myself. Wow, Flickr really does have a pool for everything. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
David Savage wrote: 2009/4/7 Matthew Hunt m...@pobox.com: On Tue, Apr 7, 2009 at 9:28 AM, David Savage ozsav...@gmail.com wrote: I know, I have added quite a few to the technically competent, but mediocre, pool myself. Wow, Flickr really does have a pool for everything. LOL Here's my latest boring photo: http://farm4.static.flickr.com/3319/3420399349_fc22fbab94_o.jpg :-) DS cool. she flashed you. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
RE: Trading resolution for depth of field
theory all you want, this makes no sense. The worse your eyesite, the worse things are in focus ( harder it is to make out fine details). Its really absurd to suggest that bad eyesite improves ANYTHING relatedt to sharpness, IT DOESNT. Like I said in my earlier posts, COC selection does not change, improve, or degrade the DOF in an image, it just changes the way you measure it. And in this case, changing the way you measure it is the opposite of real world perception. Bad eyesite doenst make out of focus areas look sharper, it makes in focus areas look blurred. JC O'Connell hifis...@gate.net -Original Message- From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of Jos from Holland Sent: Thursday, April 09, 2009 2:50 AM To: Pentax-Discuss Mail List Subject: Re: Trading resolution for depth of field Not correct, if bad eyesight leads to a percieved COC larger than the generally defined COC, a larger deviation from the focal plane is needed to see a reduced sharpness, hence the percieved DOF is larger. JC OConnell wrote: no, they have less DOF since they see less in focus JC O'Connell hifis...@gate.net -Original Message- From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of Derby Chang Sent: Wednesday, April 08, 2009 5:43 PM To: Pentax-Discuss Mail List Subject: Re: Trading resolution for depth of field Jos from Holland wrote: Exactly! Thats why people with poor eyesight are lucky: they have a larger COC MARK! -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
...only the pink... but we were discussing rocks, not abstracts - er, heavy rather than progressive. :-) LF Joseph McAllister escreveu: Floyd On Apr 7, 2009, at 13:48 , Luiz Felipe wrote: Well, I don't like them that much - all those masks, fireworks... Make mine Led Zep. Godfrey DiGiorgi escreveu: It is very simple. snip KISS rocks. ]'-) G -- Joseph McAllister pentax...@mac.com http://gallery.me.com/jomac http://web.me.com/jomac/show.me/Blog/Blog.html -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- Luiz Felipe luiz.felipe at techmit.com.br http://techmit.com.br/luizfelipe/ -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
2009/4/8 Mark Roberts msrobert...@ysu.edu David Savage wrote: http://farm4.static.flickr.com/3650/3406984942_4162539cb9_b.jpg I'm the one in red on the left with the radio shutter release in hand :-) Casual Friday in Australia, huh? Every day is casual in .au. (Too hot most of the time for formal) :-) DS -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
2009/4/8 Joseph McAllister pentax...@mac.com: On Apr 7, 2009, at 06:32 , David Savage wrote: 2009/4/7 Matthew Hunt m...@pobox.com: On Tue, Apr 7, 2009 at 9:28 AM, David Savage ozsav...@gmail.com wrote: I know, I have added quite a few to the technically competent, but mediocre, pool myself. Wow, Flickr really does have a pool for everything. LOL Here's my latest boring photo: http://farm4.static.flickr.com/3319/3420399349_fc22fbab94_o.jpg :-) Wow! Nice photo Dave. Good composition, color. I like the way you've balanced the small orange rock in the upper left hand edge with the right foot of the idiot with the uncontrolled highlight up his ass. Superb! :-) DS -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
Hehehe She's going to get such a kick out of that when I tell her. DS 2009/4/8 Luiz Felipe luiz.fel...@techmit.com.br: You may say that, but there are at least 4 using said picture as desktop background so far... permission granted and everything else. Did I say lately how I love this list??? LF Joseph McAllister escreveu: My apologies to the young lady. I had not seen enough points of interest to make a determination. On Apr 7, 2009, at 11:31 , Larry Colen wrote: On Tue, Apr 07, 2009 at 11:25:04AM -0700, Joseph McAllister wrote: Here's my latest boring photo: http://farm4.static.flickr.com/3319/3420399349_fc22fbab94_o.jpg :-) Wow! Nice photo Dave. Good composition, color. I like the way you've balanced the small orange rock in the upper left hand edge with the right foot of the idiot with the uncontrolled highlight up his ass. That looks like *her* ass to me. Joseph McAllister Lots of gear, not much time -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
...should have known better, shouldn't I? :-) Real world present hard limits to what kind of enlargement we make from film or digital alike. I don't take pics thinking of wall size enlargements to be viewed from 4 inches. I compromise. Thinking of DOF alone I'd be using the smallest possible sensor, matched to the smallest focal lenght or staying as far as possible from my subjects. But then, there are other considerations. If I could build such sensor bypassing all the other issues related to sensor size, and was able to produce a really perfect lens free of distortions and with unlimited resolution, so my camera could offer that almost unlimited DOF, would you say the limit to my circle of confusion would be the pixel? ...out of curiosity alone, since I'm rather real, and despite the unbelievable fun this thread gave me and my co-workers, this should be my last post to the matter. LF (trying to get a beautiful brunette to some DOF experiments...) JC OConnell escreveu: The problem with this post below is the word perceived. The REAL DOF increases with lower magnification, not the perceived DOF. If you could build a high quality tiny sensor and had a real short FL lens of unlimited resolution, you would end up with a camera with immense DOF capability, EVEN WITH LARGE PRINTS MADE. The viewing angles and print sizes dont matter. Its the in-camera maginification that makes the difference, a REAL difference. JC O'Connell hifis...@gate.net -Original Message- From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of Luiz Felipe Sent: Tuesday, April 07, 2009 5:55 PM To: Pentax-Discuss Mail List Subject: Re: Trading resolution for depth of field Hard as it is to remain serious in this thread, I'll try. :-) Magnification is one of the keys, and very important. For a while, let's keep the aperture and circle of confusion effects out of the equation (make them constant to all the scenarios below). So for this moment, magnification is our tool. Zooming out or stepping back would reduce image size, increasing the perceived DOF. But that's part of the problem, since we have now a pic a little smaller than we wanted. So we enlarge said photo back to the desired size, and we MAY keep the perceived DOF, as long as we don't degrade the image in the process. Best if we have some megapix stored just in case. Taking this to a limit, the circle of confusion that was acceptable in the small image becomes unacceptable in the enlargement. But there is still another point to consider - viewing distance of the final, enlarged photo. Looking too close is another way of enlarging the photo, and there go the perceived DOF and sharpness away. Keep the distance and the image keeps looking sharp - small, but sharp. Small sensor PS cameras use so small images they offer some serious DOF - offset by other considerations very quickly. As you move up in sensor size (assuming of course you use a corresponding larger image) the perceived DOF will drop. Want it back? Small image, to be enlarged later if the number of pixels remains on our side. Now, about that light at the end... ;-) LF Larry Colen escreveu: On Tue, Apr 07, 2009 at 09:32:47AM -0300, Luiz Felipe wrote: You're actually saying if one zoom out (reduce the magnification of the subject) and crop back to the desired composition the DOF will be increased, right? So the pic taken with the zoom at 35mm will present greater DOF than the one taken at 70mm, after you enlarge both to the same subject size, right? This is the premise behind point and shoots having greater depth of field than APS which has greater depth of field than Full Format. Or conversely if you want to limit DOF at a particular angle of view, you may need to go to FF. ...so the K20d has greater DOF than the *ist DS, right? Because you can shoot with a shorter lens and crop, since DOF is based on focal length squared and CoC as a linear value. Mind you, if you down res a photo from 2000x3000 pixels to 400x600 then an edge that had been 5 pixels wide is now only 1 pixel wide so even if DoF can't be changed in post processing, there will be a lot more lattitude in what you cannot see is out of focus. I love numbers... :-) LF JC OConnell escreveu: depth of field is determined solely by in camera magnification and working fstop. So cropping/format is not a factor but changing lenses from a given distance will affect DOF, likewise moving further away with the same lens and stopping down more will also both increase DOF. JC O'Connell hifis...@gate.net -Original Message- From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of Larry Colen Sent: Monday, April 06, 2009 4:35 PM To: Pentax-Discuss Mail List Subject: Trading resolution for depth of field Perhaps someone has already done the math, or the experimentation, and can just give me the answers. Scott's pictures of his
Re: Trading resolution for depth of field
On Tue, Apr 07, 2009 at 09:32:47AM -0300, Luiz Felipe wrote: You're actually saying if one zoom out (reduce the magnification of the subject) and crop back to the desired composition the DOF will be increased, right? So the pic taken with the zoom at 35mm will present greater DOF than the one taken at 70mm, after you enlarge both to the same subject size, right? This is the premise behind point and shoots having greater depth of field than APS which has greater depth of field than Full Format. Or conversely if you want to limit DOF at a particular angle of view, you may need to go to FF. ...so the K20d has greater DOF than the *ist DS, right? Because you can shoot with a shorter lens and crop, since DOF is based on focal length squared and CoC as a linear value. Mind you, if you down res a photo from 2000x3000 pixels to 400x600 then an edge that had been 5 pixels wide is now only 1 pixel wide so even if DoF can't be changed in post processing, there will be a lot more lattitude in what you cannot see is out of focus. I love numbers... :-) LF JC OConnell escreveu: depth of field is determined solely by in camera magnification and working fstop. So cropping/format is not a factor but changing lenses from a given distance will affect DOF, likewise moving further away with the same lens and stopping down more will also both increase DOF. JC O'Connell hifis...@gate.net -Original Message- From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of Larry Colen Sent: Monday, April 06, 2009 4:35 PM To: Pentax-Discuss Mail List Subject: Trading resolution for depth of field Perhaps someone has already done the math, or the experimentation, and can just give me the answers. Scott's pictures of his Nishiki inspired me to shoot some of my mongrel legnano. I rode it to lunch today, and on the way back to the office was getting some shots of it with some lupin by the side of the trail. I didn't have quite as much depth of field as I'd like, so I decided to try zooming way out and then just cropping. Smaller sensor, shorter lens, more depth of field. If the equation is linear, I should get the same DOF by downresing (downrezzing?) a longer lens over the whole sensor, as I would using a shorter lens and cropping. This would also mean that a K20 would have a lot less DOF than my K100 at the same focal length, assuming that they were blown up large enough that the sensor resolution became a factor. So, if I'm willing to trade resolution for depth of field, am I better off using a wider angle lens and cropping (my intuition says yes), or do I get the same benefit by just combining pixels (which would also reduce noise) for a larger circle of confusion? -- Luiz Felipe luiz.felipe at techmit.com.br http://techmit.com.br/luizfelipe/ -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- The fastest way to get your question answered on the net is to post the wrong answer. Larry Colen l...@red4est.comhttp://www.red4est.com/lrc -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
RE: Trading resolution for depth of field
Not sure what your getting at, but I have been talking about CONTROLLING DOF. If you want to increase or decrease it based on ANY refence, including yours, you have to change maginfication or fstop or both IN CAMERA. JC O'Connell hifis...@gate.net -Original Message- From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of Larry Colen Sent: Tuesday, April 07, 2009 2:51 PM To: Pentax-Discuss Mail List Subject: Re: Trading resolution for depth of field On Tue, Apr 07, 2009 at 02:41:08PM -0400, JC OConnell wrote: The COC thing is simply how you MEASURE perceived depth of field, no matter what COC or print size you choose, it I see. So if I don't care whether something is out of focus as long as it looks like it is in focus, then I can use the aforementioned math? -- The fastest way to get your question answered on the net is to post the wrong answer. Larry Colen l...@red4est.com http://www.red4est.com/lrc -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
On 7/4/09, Luiz Felipe, discombobulated, unleashed: ...glad to read the two of you agreeing. Now David, may I use that photo of yours as desktop background for a while? I tried to laugh quietly but my co-workers perceived the tears in my eyes and I had to show them the thread. They also would like to use the photo as background for a while... It will brighten up the orifice for sure. -- Cheers, Cotty ___/\__ || (O) | People, Places, Pastiche ||=|http://www.cottysnaps.com _ -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
Exactly! Thats why people with poor eyesight are lucky: they have a larger COC and get more DOF for free! Matthew Hunt wrote: And that's what determines depth of field: The appearance of sharpness. Every derivation of DOF begins with that criterion. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
RE: Trading resolution for depth of field
Smaller prints dont have more DOF, they're just harder to see clearly! JC O'Connell hifis...@gate.net -Original Message- From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of Joseph McAllister Sent: Tuesday, April 07, 2009 3:00 PM To: Pentax-Discuss Mail List Subject: Re: Trading resolution for depth of field On Apr 7, 2009, at 11:51 , Larry Colen wrote: On Tue, Apr 07, 2009 at 02:41:08PM -0400, JC OConnell wrote: The COC thing is simply how you MEASURE perceived depth of field, no matter what COC or print size you choose, it I see. So if I don't care whether something is out of focus as long as it looks like it is in focus, then I can use the aforementioned math? Of course! We all have many more 4 x 6 prints that are sharp vs the 11 x 14 version. That's my theory behind the thousands of dog photos in my gallery. 95% of them are not critically sharp (though it's getting better now that the sun is out) but I count on the dog owners to have smaller screens than I, and to only print 4 x 6 from the images they download. Besides, it's their dog, it's free, so it must be good. (does away with all the wedding photo terrors) Joseph McAllister pentax...@mac.com http://gallery.me.com/jomac http://web.me.com/jomac/show.me/Blog/Blog.html -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
Jos from Holland wrote: Exactly! Thats why people with poor eyesight are lucky: they have a larger COC MARK! -- der...@iinet.net.au http://members.iinet.net.au/~derbyc -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
RE: Trading resolution for depth of field
no, they have less DOF since they see less in focus JC O'Connell hifis...@gate.net -Original Message- From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of Derby Chang Sent: Wednesday, April 08, 2009 5:43 PM To: Pentax-Discuss Mail List Subject: Re: Trading resolution for depth of field Jos from Holland wrote: Exactly! Thats why people with poor eyesight are lucky: they have a larger COC MARK! -- der...@iinet.net.au http://members.iinet.net.au/~derbyc -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
Problems On Apr 7, 2009, at 06:17 , JC OConnell wrote: I don't agree with that terminology, it's his not mine. Primary non-scientific statement indicating prejudicial thought. DOF is relative sharpness Another indication of slurred thought from one who espouses pointillist correctness. of foreground and background objects in an image compared to the objects in the plane of focus. ( just my working terminology FWIW). And an admission that what JCO thinks or does only relates to JCO. The rest of us can go on about our business of taking pictures. Joseph McAllister Lots of gear, not much time http://gallery.me.com/jomac http://web.me.com/jomac/show.me/Blog/Blog.html -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
...still without words... hehehehehehehehehehehehehe David Savage escreveu: 2009/4/7 Matthew Hunt m...@pobox.com: On Tue, Apr 7, 2009 at 9:28 AM, David Savage ozsav...@gmail.com wrote: I know, I have added quite a few to the technically competent, but mediocre, pool myself. Wow, Flickr really does have a pool for everything. LOL Here's my latest boring photo: http://farm4.static.flickr.com/3319/3420399349_fc22fbab94_o.jpg :-) DS -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- Luiz Felipe luiz.felipe at techmit.com.br http://techmit.com.br/luizfelipe/ -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
RE: Trading resolution for depth of field
Instead of making an unsupported assertion why don't you provide a formula for calculating depth of field? Then we will all be able to test your assertion. I have provided a formula which shows quite clearly that you are wrong. The calculation uses coc as a factor. The formula for coc depends on viewing distance and print size, therefore by changing either of these the coc changes. If the coc changes, the depth of field changes. You can't argue with the numbers. Give us a formula which shows you are right, then people might start to take you seriously. Jose NO WAY JOSE. you can never change the dof after the shot, DOF is an in camera thingy... you have to change the in camera image magnification or f-stop to change the image DOF. JC O'Connell hifis...@gate.net Coc is always a factor. You can change the viewing distance or the print size, and the depth of field changes. Bob The question was regarding relative DOF, COC is not a factor. The only way to increase DOF from whatever your reference is, is to decrease IN CAMERA magnification or increase f-stop number. All that other stuff is moot. You cant change the relative DOF of an image after you shoot it. JC O'Connell hifis...@gate.net -Original Message- From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of Larry Colen Sent: Monday, April 06, 2009 5:47 PM To: Pentax-Discuss Mail List Subject: Re: Trading resolution for depth of field On Mon, Apr 06, 2009 at 10:32:37PM +0100, Bob W wrote: So, if I'm willing to trade resolution for depth of field, am I better off using a wider angle lens and cropping (my intuition says yes), or do I get the same benefit by just combining pixels (which would also reduce noise) for a larger circle of confusion? To calculate the nearest (dn) and furthest (df) points in focus use the following formulae: dn = U * F^2 / [F^2 + (U * c * f)] df = U * F^2 / [F^2 - (U * c * f)] Ah. Thanks. Focal length is second order factor, circle of confusion is first order, so focal length has a greater effect on DOF, than CoC (pixel size). where c = circle of confusion U = subject distance F = focal length f = f-number To calculate the circle of confusion c = (v * D) / (1000 * S) where v = film format / image size D = viewing distance S = print size Source: The Professional Guide to Photo Data, 3rd edition, by Richard Platt. Very easy with a spreadsheet. Bob -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
RE: Trading resolution for depth of field
Afyer 35 years of experience, I dont need no stinking formula, everybody knows the depth of field is image locked once you make the exposure. To change it ( increase or decrease the relative depth of field ), you have to change the in-camera magnification or fstop before shooting. You cant manipulate more or less image DOF ***after the exposure ***. Making a print larger or smaller doesnt change DOF, nor does declaring a the COC bigger or larger. To increase or decrease the image DOF you have make changes BEFORE the exposureAFTER is impossible. While not a formula, its a rule, DOF is proportional to f-number and inversely proportional to in-camera image magnification. Relative DOF = (f-stop number)/(in camera image magnification). These are the only two factors that increase or decrease relative DOF. These cannot be changed after the exposure. NOTE how, COC, Format, focal length, print size, etc do not matter. ONLY in-camera magnification changes and/or f-ratio changes can increase or decrease the relative DOF. Its very basic. JC O'Connell hifis...@gate.net -Original Message- From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of Bob W Sent: Tuesday, April 07, 2009 4:03 AM To: 'Pentax-Discuss Mail List' Subject: RE: Trading resolution for depth of field Instead of making an unsupported assertion why don't you provide a formula for calculating depth of field? Then we will all be able to test your assertion. I have provided a formula which shows quite clearly that you are wrong. The calculation uses coc as a factor. The formula for coc depends on viewing distance and print size, therefore by changing either of these the coc changes. If the coc changes, the depth of field changes. You can't argue with the numbers. Give us a formula which shows you are right, then people might start to take you seriously. Jose NO WAY JOSE. you can never change the dof after the shot, DOF is an in camera thingy... you have to change the in camera image magnification or f-stop to change the image DOF. JC O'Connell hifis...@gate.net Coc is always a factor. You can change the viewing distance or the print size, and the depth of field changes. Bob The question was regarding relative DOF, COC is not a factor. The only way to increase DOF from whatever your reference is, is to decrease IN CAMERA magnification or increase f-stop number. All that other stuff is moot. You cant change the relative DOF of an image after you shoot it. JC O'Connell hifis...@gate.net -Original Message- From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of Larry Colen Sent: Monday, April 06, 2009 5:47 PM To: Pentax-Discuss Mail List Subject: Re: Trading resolution for depth of field On Mon, Apr 06, 2009 at 10:32:37PM +0100, Bob W wrote: So, if I'm willing to trade resolution for depth of field, am I better off using a wider angle lens and cropping (my intuition says yes), or do I get the same benefit by just combining pixels (which would also reduce noise) for a larger circle of confusion? To calculate the nearest (dn) and furthest (df) points in focus use the following formulae: dn = U * F^2 / [F^2 + (U * c * f)] df = U * F^2 / [F^2 - (U * c * f)] Ah. Thanks. Focal length is second order factor, circle of confusion is first order, so focal length has a greater effect on DOF, than CoC (pixel size). where c = circle of confusion U = subject distance F = focal length f = f-number To calculate the circle of confusion c = (v * D) / (1000 * S) where v = film format / image size D = viewing distance S = print size Source: The Professional Guide to Photo Data, 3rd edition, by Richard Platt. Very easy with a spreadsheet. Bob -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
On Tue, Apr 7, 2009 at 4:02 AM, Bob W p...@web-options.com wrote: You can't argue with the numbers. OR A BRICK WALL. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
You're actually saying if one zoom out (reduce the magnification of the subject) and crop back to the desired composition the DOF will be increased, right? So the pic taken with the zoom at 35mm will present greater DOF than the one taken at 70mm, after you enlarge both to the same subject size, right? ...so the K20d has greater DOF than the *ist DS, right? I love numbers... :-) LF JC OConnell escreveu: depth of field is determined solely by in camera magnification and working fstop. So cropping/format is not a factor but changing lenses from a given distance will affect DOF, likewise moving further away with the same lens and stopping down more will also both increase DOF. JC O'Connell hifis...@gate.net -Original Message- From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of Larry Colen Sent: Monday, April 06, 2009 4:35 PM To: Pentax-Discuss Mail List Subject: Trading resolution for depth of field Perhaps someone has already done the math, or the experimentation, and can just give me the answers. Scott's pictures of his Nishiki inspired me to shoot some of my mongrel legnano. I rode it to lunch today, and on the way back to the office was getting some shots of it with some lupin by the side of the trail. I didn't have quite as much depth of field as I'd like, so I decided to try zooming way out and then just cropping. Smaller sensor, shorter lens, more depth of field. If the equation is linear, I should get the same DOF by downresing (downrezzing?) a longer lens over the whole sensor, as I would using a shorter lens and cropping. This would also mean that a K20 would have a lot less DOF than my K100 at the same focal length, assuming that they were blown up large enough that the sensor resolution became a factor. So, if I'm willing to trade resolution for depth of field, am I better off using a wider angle lens and cropping (my intuition says yes), or do I get the same benefit by just combining pixels (which would also reduce noise) for a larger circle of confusion? -- Luiz Felipe luiz.felipe at techmit.com.br http://techmit.com.br/luizfelipe/ -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
This is a simple issue. Bob is speaking of perceived depth of filed on a viewed print. JCO is speaking of critical depth of field in respect to the ability of a given lens to resolve detail. Both are correct, but each is discussing an entirely different matter. Let it go. On Apr 7, 2009, at 4:02 AM, Bob W wrote: Instead of making an unsupported assertion why don't you provide a formula for calculating depth of field? Then we will all be able to test your assertion. I have provided a formula which shows quite clearly that you are wrong. The calculation uses coc as a factor. The formula for coc depends on viewing distance and print size, therefore by changing either of these the coc changes. If the coc changes, the depth of field changes. You can't argue with the numbers. Give us a formula which shows you are right, then people might start to take you seriously. Jose NO WAY JOSE. you can never change the dof after the shot, DOF is an in camera thingy... you have to change the in camera image magnification or f-stop to change the image DOF. JC O'Connell hifis...@gate.net Coc is always a factor. You can change the viewing distance or the print size, and the depth of field changes. Bob The question was regarding relative DOF, COC is not a factor. The only way to increase DOF from whatever your reference is, is to decrease IN CAMERA magnification or increase f-stop number. All that other stuff is moot. You cant change the relative DOF of an image after you shoot it. JC O'Connell hifis...@gate.net -Original Message- From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of Larry Colen Sent: Monday, April 06, 2009 5:47 PM To: Pentax-Discuss Mail List Subject: Re: Trading resolution for depth of field On Mon, Apr 06, 2009 at 10:32:37PM +0100, Bob W wrote: So, if I'm willing to trade resolution for depth of field, am I better off using a wider angle lens and cropping (my intuition says yes), or do I get the same benefit by just combining pixels (which would also reduce noise) for a larger circle of confusion? To calculate the nearest (dn) and furthest (df) points in focus use the following formulae: dn = U * F^2 / [F^2 + (U * c * f)] df = U * F^2 / [F^2 - (U * c * f)] Ah. Thanks. Focal length is second order factor, circle of confusion is first order, so focal length has a greater effect on DOF, than CoC (pixel size). where c = circle of confusion U = subject distance F = focal length f = f-number To calculate the circle of confusion c = (v * D) / (1000 * S) where v = film format / image size D = viewing distance S = print size Source: The Professional Guide to Photo Data, 3rd edition, by Richard Platt. Very easy with a spreadsheet. Bob -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
No point in hurling insults. JCO is right in respect to the ability of a lens to resolve. Bob is correct in regard to viewing a print that's hanging on a wall. On Apr 7, 2009, at 7:16 AM, Matthew Hunt wrote: On Tue, Apr 7, 2009 at 4:02 AM, Bob W p...@web-options.com wrote: You can't argue with the numbers. OR A BRICK WALL. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
RE: Trading resolution for depth of field
YES - right. JC O'Connell hifis...@gate.net -Original Message- From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of Luiz Felipe Sent: Tuesday, April 07, 2009 8:33 AM To: Pentax-Discuss Mail List Subject: Re: Trading resolution for depth of field You're actually saying if one zoom out (reduce the magnification of the subject) and crop back to the desired composition the DOF will be increased, right? So the pic taken with the zoom at 35mm will present greater DOF than the one taken at 70mm, after you enlarge both to the same subject size, right? ...so the K20d has greater DOF than the *ist DS, right? I love numbers... :-) LF JC OConnell escreveu: depth of field is determined solely by in camera magnification and working fstop. So cropping/format is not a factor but changing lenses from a given distance will affect DOF, likewise moving further away with the same lens and stopping down more will also both increase DOF. JC O'Connell hifis...@gate.net -Original Message- From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of Larry Colen Sent: Monday, April 06, 2009 4:35 PM To: Pentax-Discuss Mail List Subject: Trading resolution for depth of field Perhaps someone has already done the math, or the experimentation, and can just give me the answers. Scott's pictures of his Nishiki inspired me to shoot some of my mongrel legnano. I rode it to lunch today, and on the way back to the office was getting some shots of it with some lupin by the side of the trail. I didn't have quite as much depth of field as I'd like, so I decided to try zooming way out and then just cropping. Smaller sensor, shorter lens, more depth of field. If the equation is linear, I should get the same DOF by downresing (downrezzing?) a longer lens over the whole sensor, as I would using a shorter lens and cropping. This would also mean that a K20 would have a lot less DOF than my K100 at the same focal length, assuming that they were blown up large enough that the sensor resolution became a factor. So, if I'm willing to trade resolution for depth of field, am I better off using a wider angle lens and cropping (my intuition says yes), or do I get the same benefit by just combining pixels (which would also reduce noise) for a larger circle of confusion? -- Luiz Felipe luiz.felipe at techmit.com.br http://techmit.com.br/luizfelipe/ -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
RE: Trading resolution for depth of field
NO I DISAGREE. Image DOF is the RELATIVE sharpness of objects in front of, and behind, the actual plane of focus. TO INCREASE OR DECREASE this relative sharpness you have to change the incamera magnification or f-stop. PRINT SIZE has nothing to do with changing the DOF of an image. While you can argue all day long that making a print smaller and smaller increases the perceived DOF, I dont, because all it does is make it harder to see the **same DOF**, its doesnt actually change the image DOF at all. Furthermore, I disagree with using the term critial to define DOF. Its not critical, its what it is, and thats simply the difference in sharpness of foreground and background objects relative to objects in the plane of focus. It doesnt have to be some critical barely perceivable difference, sometimes its huge and obvious. but in any case, if you want to increase or decrease that DOF, you need to know what CHANGES it, and what DOES NOT. JC O'Connell hifis...@gate.net -Original Message- From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of Paul Stenquist Sent: Tuesday, April 07, 2009 8:35 AM To: Pentax-Discuss Mail List Subject: Re: Trading resolution for depth of field This is a simple issue. Bob is speaking of perceived depth of filed on a viewed print. JCO is speaking of critical depth of field in respect to the ability of a given lens to resolve detail. Both are correct, but each is discussing an entirely different matter. Let it go. On Apr 7, 2009, at 4:02 AM, Bob W wrote: Instead of making an unsupported assertion why don't you provide a formula for calculating depth of field? Then we will all be able to test your assertion. I have provided a formula which shows quite clearly that you are wrong. The calculation uses coc as a factor. The formula for coc depends on viewing distance and print size, therefore by changing either of these the coc changes. If the coc changes, the depth of field changes. You can't argue with the numbers. Give us a formula which shows you are right, then people might start to take you seriously. Jose NO WAY JOSE. you can never change the dof after the shot, DOF is an in camera thingy... you have to change the in camera image magnification or f-stop to change the image DOF. JC O'Connell hifis...@gate.net Coc is always a factor. You can change the viewing distance or the print size, and the depth of field changes. Bob The question was regarding relative DOF, COC is not a factor. The only way to increase DOF from whatever your reference is, is to decrease IN CAMERA magnification or increase f-stop number. All that other stuff is moot. You cant change the relative DOF of an image after you shoot it. JC O'Connell hifis...@gate.net -Original Message- From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of Larry Colen Sent: Monday, April 06, 2009 5:47 PM To: Pentax-Discuss Mail List Subject: Re: Trading resolution for depth of field On Mon, Apr 06, 2009 at 10:32:37PM +0100, Bob W wrote: So, if I'm willing to trade resolution for depth of field, am I better off using a wider angle lens and cropping (my intuition says yes), or do I get the same benefit by just combining pixels (which would also reduce noise) for a larger circle of confusion? To calculate the nearest (dn) and furthest (df) points in focus use the following formulae: dn = U * F^2 / [F^2 + (U * c * f)] df = U * F^2 / [F^2 - (U * c * f)] Ah. Thanks. Focal length is second order factor, circle of confusion is first order, so focal length has a greater effect on DOF, than CoC (pixel size). where c = circle of confusion U = subject distance F = focal length f = f-number To calculate the circle of confusion c = (v * D) / (1000 * S) where v = film format / image size D = viewing distance S = print size Source: The Professional Guide to Photo Data, 3rd edition, by Richard Platt. Very easy with a spreadsheet. Bob -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
RE: Trading resolution for depth of field
I agree on no need to get personal. But print size has zero to do with changing DOF. Smaller or larger, you cant change the image DOF with printing techniques. In camera magnification and f-number are the only factors... JC O'Connell hifis...@gate.net -Original Message- From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of Paul Stenquist Sent: Tuesday, April 07, 2009 8:36 AM To: Pentax-Discuss Mail List Subject: Re: Trading resolution for depth of field No point in hurling insults. JCO is right in respect to the ability of a lens to resolve. Bob is correct in regard to viewing a print that's hanging on a wall. On Apr 7, 2009, at 7:16 AM, Matthew Hunt wrote: On Tue, Apr 7, 2009 at 4:02 AM, Bob W p...@web-options.com wrote: You can't argue with the numbers. OR A BRICK WALL. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
On Tue, 7 Apr 2009, Paul Stenquist wrote: This is a simple issue. Bob is speaking of perceived depth of filed on a viewed print. JCO is speaking of critical depth of field in respect to the ability of a given lens to resolve detail. Both are correct, but each is discussing an entirely different matter. Let it go. ... but as I'm sure we will discover, only one is correct. ;-) -Cory -- * * Cory Papenfuss, Ph.D. Electrical Engineering, PPSEL-IA* * Research Associate, Vibrations and Acoustics Laboratory * * Mechanical Engineering* * Virginia Polytechnic Institute and State University * * -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
This theoretical crap is boring. Quite wasting your time mass debating the theory go put it into practice by taking some interesting photos. DS 2009/4/7 JC OConnell hifis...@gate.net NO I DISAGREE. Image DOF is the RELATIVE sharpness of objects in front of, and behind, the actual plane of focus. TO INCREASE OR DECREASE this relative sharpness you have to change the incamera magnification or f-stop. PRINT SIZE has nothing to do with changing the DOF of an image. While you can argue all day long that making a print smaller and smaller increases the perceived DOF, I dont, because all it does is make it harder to see the **same DOF**, its doesnt actually change the image DOF at all. Furthermore, I disagree with using the term critial to define DOF. Its not critical, its what it is, and thats simply the difference in sharpness of foreground and background objects relative to objects in the plane of focus. It doesnt have to be some critical barely perceivable difference, sometimes its huge and obvious. but in any case, if you want to increase or decrease that DOF, you need to know what CHANGES it, and what DOES NOT. JC O'Connell hifis...@gate.net -Original Message- From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of Paul Stenquist Sent: Tuesday, April 07, 2009 8:35 AM To: Pentax-Discuss Mail List Subject: Re: Trading resolution for depth of field This is a simple issue. Bob is speaking of perceived depth of filed on a viewed print. JCO is speaking of critical depth of field in respect to the ability of a given lens to resolve detail. Both are correct, but each is discussing an entirely different matter. Let it go. On Apr 7, 2009, at 4:02 AM, Bob W wrote: Instead of making an unsupported assertion why don't you provide a formula for calculating depth of field? Then we will all be able to test your assertion. I have provided a formula which shows quite clearly that you are wrong. The calculation uses coc as a factor. The formula for coc depends on viewing distance and print size, therefore by changing either of these the coc changes. If the coc changes, the depth of field changes. You can't argue with the numbers. Give us a formula which shows you are right, then people might start to take you seriously. Jose NO WAY JOSE. you can never change the dof after the shot, DOF is an in camera thingy... you have to change the in camera image magnification or f-stop to change the image DOF. JC O'Connell hifis...@gate.net Coc is always a factor. You can change the viewing distance or the print size, and the depth of field changes. Bob The question was regarding relative DOF, COC is not a factor. The only way to increase DOF from whatever your reference is, is to decrease IN CAMERA magnification or increase f-stop number. All that other stuff is moot. You cant change the relative DOF of an image after you shoot it. JC O'Connell hifis...@gate.net -Original Message- From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of Larry Colen Sent: Monday, April 06, 2009 5:47 PM To: Pentax-Discuss Mail List Subject: Re: Trading resolution for depth of field On Mon, Apr 06, 2009 at 10:32:37PM +0100, Bob W wrote: So, if I'm willing to trade resolution for depth of field, am I better off using a wider angle lens and cropping (my intuition says yes), or do I get the same benefit by just combining pixels (which would also reduce noise) for a larger circle of confusion? To calculate the nearest (dn) and furthest (df) points in focus use the following formulae: dn = U * F^2 / [F^2 + (U * c * f)] df = U * F^2 / [F^2 - (U * c * f)] Ah. Thanks. Focal length is second order factor, circle of confusion is first order, so focal length has a greater effect on DOF, than CoC (pixel size). where c = circle of confusion U = subject distance F = focal length f = f-number To calculate the circle of confusion c = (v * D) / (1000 * S) where v = film format / image size D = viewing distance S = print size Source: The Professional Guide to Photo Data, 3rd edition, by Richard Platt. Very easy with a spreadsheet. Bob -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- PDML Pentax-Discuss Mail List PDML
RE: Trading resolution for depth of field
Correct, either you CAN change image DOF via printing or you CANT. Forget the former. JC O'Connell hifis...@gate.net -Original Message- From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of Cory Papenfuss Sent: Tuesday, April 07, 2009 8:58 AM To: Pentax-Discuss Mail List Subject: Re: Trading resolution for depth of field On Tue, 7 Apr 2009, Paul Stenquist wrote: This is a simple issue. Bob is speaking of perceived depth of filed on a viewed print. JCO is speaking of critical depth of field in respect to the ability of a given lens to resolve detail. Both are correct, but each is discussing an entirely different matter. Let it go. ... but as I'm sure we will discover, only one is correct. ;-) -Cory -- * * Cory Papenfuss, Ph.D. Electrical Engineering, PPSEL-IA * * Research Associate, Vibrations and Acoustics Laboratory * * Mechanical Engineering * * Virginia Polytechnic Institute and State University * * -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
On Tue, Apr 7, 2009 at 8:36 AM, Paul Stenquist pnstenqu...@comcast.net wrote: No point in hurling insults. JCO is right in respect to the ability of a lens to resolve. Bob is correct in regard to viewing a print that's hanging on a wall. What criterion do you use to define the ability of a lens to resolve? Where does that criterion come from? -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
RE: Trading resolution for depth of field
THEORETICAL CRAP? Screw you, this is REAL WORLD BASIC photograhpy techniques. I would think that any photographer needs to know how to control DOF. You cant just go take pictures without some basic knowledge of what controls what in your images. And the fundemental knowledge of what can be changed later and what can't certainly doesnt hurt either. JC O'Connell hifis...@gate.net -Original Message- From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of David Savage Sent: Tuesday, April 07, 2009 8:58 AM To: Pentax-Discuss Mail List Subject: Re: Trading resolution for depth of field This theoretical crap is boring. Quite wasting your time mass debating the theory go put it into practice by taking some interesting photos. DS 2009/4/7 JC OConnell hifis...@gate.net NO I DISAGREE. Image DOF is the RELATIVE sharpness of objects in front of, and behind, the actual plane of focus. TO INCREASE OR DECREASE this relative sharpness you have to change the incamera magnification or f-stop. PRINT SIZE has nothing to do with changing the DOF of an image. While you can argue all day long that making a print smaller and smaller increases the perceived DOF, I dont, because all it does is make it harder to see the **same DOF**, its doesnt actually change the image DOF at all. Furthermore, I disagree with using the term critial to define DOF. Its not critical, its what it is, and thats simply the difference in sharpness of foreground and background objects relative to objects in the plane of focus. It doesnt have to be some critical barely perceivable difference, sometimes its huge and obvious. but in any case, if you want to increase or decrease that DOF, you need to know what CHANGES it, and what DOES NOT. JC O'Connell hifis...@gate.net -Original Message- From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of Paul Stenquist Sent: Tuesday, April 07, 2009 8:35 AM To: Pentax-Discuss Mail List Subject: Re: Trading resolution for depth of field This is a simple issue. Bob is speaking of perceived depth of filed on a viewed print. JCO is speaking of critical depth of field in respect to the ability of a given lens to resolve detail. Both are correct, but each is discussing an entirely different matter. Let it go. On Apr 7, 2009, at 4:02 AM, Bob W wrote: Instead of making an unsupported assertion why don't you provide a formula for calculating depth of field? Then we will all be able to test your assertion. I have provided a formula which shows quite clearly that you are wrong. The calculation uses coc as a factor. The formula for coc depends on viewing distance and print size, therefore by changing either of these the coc changes. If the coc changes, the depth of field changes. You can't argue with the numbers. Give us a formula which shows you are right, then people might start to take you seriously. Jose NO WAY JOSE. you can never change the dof after the shot, DOF is an in camera thingy... you have to change the in camera image magnification or f-stop to change the image DOF. JC O'Connell hifis...@gate.net Coc is always a factor. You can change the viewing distance or the print size, and the depth of field changes. Bob The question was regarding relative DOF, COC is not a factor. The only way to increase DOF from whatever your reference is, is to decrease IN CAMERA magnification or increase f-stop number. All that other stuff is moot. You cant change the relative DOF of an image after you shoot it. JC O'Connell hifis...@gate.net -Original Message- From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of Larry Colen Sent: Monday, April 06, 2009 5:47 PM To: Pentax-Discuss Mail List Subject: Re: Trading resolution for depth of field On Mon, Apr 06, 2009 at 10:32:37PM +0100, Bob W wrote: So, if I'm willing to trade resolution for depth of field, am I better off using a wider angle lens and cropping (my intuition says yes), or do I get the same benefit by just combining pixels (which would also reduce noise) for a larger circle of confusion? To calculate the nearest (dn) and furthest (df) points in focus use the following formulae: dn = U * F^2 / [F^2 + (U * c * f)] df = U * F^2 / [F^2 - (U * c * f)] Ah. Thanks. Focal length is second order factor, circle of confusion is first order, so focal length has a greater effect on DOF, than CoC (pixel size). where c = circle of confusion U = subject distance F = focal length f = f-number To calculate the circle of confusion c = (v * D) / (1000 * S) where v = film format / image size D = viewing distance S = print size Source: The Professional Guide to Photo Data, 3rd edition, by Richard Platt. Very easy with a spreadsheet
RE: Trading resolution for depth of field
I dont agree with that terminology, it's his not mine. DOF is relative sharpness of foreground and background objects in an image compared to the objects in the plane of focus. ( just my working terminology FWIW). JC O'Connell hifis...@gate.net -Original Message- From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of Matthew Hunt Sent: Tuesday, April 07, 2009 9:12 AM To: Pentax-Discuss Mail List Subject: Re: Trading resolution for depth of field On Tue, Apr 7, 2009 at 8:36 AM, Paul Stenquist pnstenqu...@comcast.net wrote: No point in hurling insults. JCO is right in respect to the ability of a lens to resolve. Bob is correct in regard to viewing a print that's hanging on a wall. What criterion do you use to define the ability of a lens to resolve? Where does that criterion come from? -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
On Tue, Apr 7, 2009 at 9:13 AM, JC OConnell hifis...@gate.net wrote: THEORETICAL CRAP? Screw you, this is REAL WORLD BASIC photograhpy techniques. I would think that any photographer needs to know how to control DOF. You cant just go take pictures without some basic knowledge of what controls what in your images. And the fundemental knowledge of what can be changed later and what can't certainly doesnt hurt either. I think the point is that we don't need to know numbers, equations or theories to know that the wider the aperture the narrower the dof and vice-versa. Working with post-processing programmes lets you know what can be changed later and what can't. I agree with you, BTW, that DOF is a function of camera, not processing, and the thought that these things can be applied or altered in photoshop is wrong-headed (but that's just me). But you can bang my head with all the numbers and theories you want, until I go do it over and over, I'm not going to get it. Some people like the theory behind things, and that's fine, too. But we can't forget what the underlying theory is about: going out and taking photos! ;-) cheers, frank -- Sharpness is a bourgeois concept. -Henri Cartier-Bresson -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
Whatever floats your boat sweetie. 2009/4/7 JC OConnell hifis...@gate.net: Screw you -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
On Tue, Apr 7, 2009 at 9:17 AM, JC OConnell hifis...@gate.net wrote: I dont agree with that terminology, it's his not mine. DOF is relative sharpness of foreground and background objects in an image compared to the objects in the plane of focus. ( just my working terminology FWIW). So, if a certain object in the foreground is half as sharp (or twice as blurred) as an object in the plane of focus, is it within the DOF? What if it's a third as sharp? A quarter? Where do you draw the line? To define the DOF, you need a concept of acceptable sharpness or acceptable circle of confusion. These criteria typically arise from assumptions about the final print (film size, print size, viewing distance...). In our previous discussion, I provided a number of reputable citations discussing the origin of these criteria. If you had read them, instead of screaming unsubstantiated assertions back at me, we wouldn't have to go through this again. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
2009/4/7 frank theriault knarftheria...@gmail.com: But you can bang my head with all the numbers and theories you want, until I go do it over and over, I'm not going to get it. Some people like the theory behind things, and that's fine, too. But we can't forget what the underlying theory is about: going out and taking photos! Amen! All also add that there thousands upon thousand of technically competent, but mind numbingly boring, photos on the inter web. I know, I have added quite a few to the technically competent, but mediocre, pool myself. DS -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
...there IS a light at the end... LF Doug Brewer escreveu: David Savage wrote: 2009/4/7 Matthew Hunt m...@pobox.com: On Tue, Apr 7, 2009 at 9:28 AM, David Savage ozsav...@gmail.com wrote: I know, I have added quite a few to the technically competent, but mediocre, pool myself. Wow, Flickr really does have a pool for everything. LOL Here's my latest boring photo: http://farm4.static.flickr.com/3319/3420399349_fc22fbab94_o.jpg :-) DS cool. she flashed you. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- Luiz Felipe luiz.felipe at techmit.com.br http://techmit.com.br/luizfelipe/ -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
RE: Trading resolution for depth of field
Im NOT the guy who was demanding formulae. As far as fstop goes, yes most people know that stopping down increases DOF and opening up decreases it, but the only other factor that affects DOF, in-camera image magnification, is not very well known. That's mainly why I posted on this thread. JC O'Connell hifis...@gate.net -Original Message- From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of frank theriault Sent: Tuesday, April 07, 2009 9:21 AM To: Pentax-Discuss Mail List Subject: Re: Trading resolution for depth of field On Tue, Apr 7, 2009 at 9:13 AM, JC OConnell hifis...@gate.net wrote: THEORETICAL CRAP? Screw you, this is REAL WORLD BASIC photograhpy techniques. I would think that any photographer needs to know how to control DOF. You cant just go take pictures without some basic knowledge of what controls what in your images. And the fundemental knowledge of what can be changed later and what can't certainly doesnt hurt either. I think the point is that we don't need to know numbers, equations or theories to know that the wider the aperture the narrower the dof and vice-versa. Working with post-processing programmes lets you know what can be changed later and what can't. I agree with you, BTW, that DOF is a function of camera, not processing, and the thought that these things can be applied or altered in photoshop is wrong-headed (but that's just me). But you can bang my head with all the numbers and theories you want, until I go do it over and over, I'm not going to get it. Some people like the theory behind things, and that's fine, too. But we can't forget what the underlying theory is about: going out and taking photos! ;-) cheers, frank -- Sharpness is a bourgeois concept. -Henri Cartier-Bresson -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
2009/4/7 Doug Brewer d...@alphoto.com: David Savage wrote: 2009/4/7 Matthew Hunt m...@pobox.com: On Tue, Apr 7, 2009 at 9:28 AM, David Savage ozsav...@gmail.com wrote: I know, I have added quite a few to the technically competent, but mediocre, pool myself. Wow, Flickr really does have a pool for everything. LOL Here's my latest boring photo: http://farm4.static.flickr.com/3319/3420399349_fc22fbab94_o.jpg :-) DS cool. she flashed you. I remotly controlled it too. The Jedi mind trick is an amazing thing. DS -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
RE: Trading resolution for depth of field
you are trying to define some sort of absolute DOF which really doesnt exist unless you consider a certain COC as perfect. The entire thread and original post was all about the relative DOF ( how to increase or decrease DOF in an image relative to ANY reference DOF ). JC O'Connell hifis...@gate.net -Original Message- From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of Matthew Hunt Sent: Tuesday, April 07, 2009 9:27 AM To: Pentax-Discuss Mail List Subject: Re: Trading resolution for depth of field On Tue, Apr 7, 2009 at 9:17 AM, JC OConnell hifis...@gate.net wrote: I dont agree with that terminology, it's his not mine. DOF is relative sharpness of foreground and background objects in an image compared to the objects in the plane of focus. ( just my working terminology FWIW). So, if a certain object in the foreground is half as sharp (or twice as blurred) as an object in the plane of focus, is it within the DOF? What if it's a third as sharp? A quarter? Where do you draw the line? To define the DOF, you need a concept of acceptable sharpness or acceptable circle of confusion. These criteria typically arise from assumptions about the final print (film size, print size, viewing distance...). In our previous discussion, I provided a number of reputable citations discussing the origin of these criteria. If you had read them, instead of screaming unsubstantiated assertions back at me, we wouldn't have to go through this again. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
RE: Trading resolution for depth of field
Its important to remember, that while good technique cant improve a bad image, bad technique CAN destroy a good image. Technique isnt everything, but it doesnt hurt to get it right. JC O'Connell hifis...@gate.net -Original Message- From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of David Savage Sent: Tuesday, April 07, 2009 9:28 AM To: Pentax-Discuss Mail List Subject: Re: Trading resolution for depth of field 2009/4/7 frank theriault knarftheria...@gmail.com: But you can bang my head with all the numbers and theories you want, until I go do it over and over, I'm not going to get it. Some people like the theory behind things, and that's fine, too. But we can't forget what the underlying theory is about: going out and taking photos! Amen! All also add that there thousands upon thousand of technically competent, but mind numbingly boring, photos on the inter web. I know, I have added quite a few to the technically competent, but mediocre, pool myself. DS -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
This is true. 2009/4/7 JC OConnell hifis...@gate.net: Its important to remember, that while good technique cant improve a bad image, bad technique CAN destroy a good image. Technique isnt everything, but it doesnt hurt to get it right. JC O'Connell hifis...@gate.net -Original Message- From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of David Savage Sent: Tuesday, April 07, 2009 9:28 AM To: Pentax-Discuss Mail List Subject: Re: Trading resolution for depth of field 2009/4/7 frank theriault knarftheria...@gmail.com: But you can bang my head with all the numbers and theories you want, until I go do it over and over, I'm not going to get it. Some people like the theory behind things, and that's fine, too. But we can't forget what the underlying theory is about: going out and taking photos! Amen! All also add that there thousands upon thousand of technically competent, but mind numbingly boring, photos on the inter web. I know, I have added quite a few to the technically competent, but mediocre, pool myself. DS -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
On Tue, Apr 7, 2009 at 9:49 AM, JC OConnell hifis...@gate.net wrote: you are trying to define some sort of absolute DOF which really doesnt exist unless you consider a certain COC as perfect. Actually, I'm claiming the opposite. That any definition depends on assumptions of the acceptable circle of confusion, and therefore is not absolute. The entire thread and original post was all about the relative DOF ( how to increase or decrease DOF in an image relative to ANY reference DOF ). But your claims regarding relative DOF are only valid if the image format (film size, crop factor, whatever you want to call it) is constant. A change in format leads to a change in allowable CoC, which you're dropping on the floor. If you dispute that the allowable CoC is different for different formats, then you are the one who is claiming there's an absolute DOF. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
RE: Trading resolution for depth of field
JC O'Connell hifis...@gate.net -Original Message- From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of Matthew Hunt The entire thread and original post was all about the relative DOF ( how to increase or decrease DOF in an image relative to ANY reference DOF ). But your claims regarding relative DOF are only valid if the image format (film size, crop factor, whatever you want to call it) is constant. A change in format leads to a change in allowable CoC, which you're dropping on the floor. If you dispute that the allowable CoC is different for different formats, then you are the one who is claiming there's an absolute DOF. === NO NO NO NO, My post is ALL INCLUSIVE. The only thing that affects (increases or decreases) the image DOF is : (the image magnification in-camera) (f-stop used). Format, crop factors, COC, print size, etc, blah blah blah have ZERO effect on DOF. That is the common myth I am trying to dispell. Its all about image magnification and f-stop and THATS IT. Changing the format, film size, COC means nothing..ONLY changes to the image magnification and f-stop change the DOF. JCO -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
On Tue, Apr 7, 2009 at 9:47 AM, JC OConnell hifis...@gate.net wrote: Im NOT the guy who was demanding formulae. As far as fstop goes, yes most people know that stopping down increases DOF and opening up decreases it, but the only other factor that affects DOF, in-camera image magnification, is not very well known. That's mainly why I posted on this thread. Fair enough... cheers, frank -- Sharpness is a bourgeois concept. -Henri Cartier-Bresson -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
RE: Trading resolution for depth of field- IMAGE MAGNIFICATION
For the sake of clarity, I neglected to post the definition of in-camera image magnification (M). in-camera image magnification is the ratio of object size to image size. Longer lenses and shorter object distances increase magnification, shorter lenses and longer distances decrease magnification. JC O'Connell hifis...@gate.net -- Sharpness is a bourgeois concept. -Henri Cartier-Bresson -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
...glad to read the two of you agreeing. Now David, may I use that photo of yours as desktop background for a while? I tried to laugh quietly but my co-workers perceived the tears in my eyes and I had to show them the thread. They also would like to use the photo as background for a while... LF David Savage escreveu: This is true. 2009/4/7 JC OConnell hifis...@gate.net: Its important to remember, that while good technique cant improve a bad image, bad technique CAN destroy a good image. Technique isnt everything, but it doesnt hurt to get it right. JC O'Connell hifis...@gate.net -Original Message- From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of David Savage Sent: Tuesday, April 07, 2009 9:28 AM To: Pentax-Discuss Mail List Subject: Re: Trading resolution for depth of field 2009/4/7 frank theriault knarftheria...@gmail.com: But you can bang my head with all the numbers and theories you want, until I go do it over and over, I'm not going to get it. Some people like the theory behind things, and that's fine, too. But we can't forget what the underlying theory is about: going out and taking photos! Amen! All also add that there thousands upon thousand of technically competent, but mind numbingly boring, photos on the inter web. I know, I have added quite a few to the technically competent, but mediocre, pool myself. DS -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- Luiz Felipe luiz.felipe at techmit.com.br http://techmit.com.br/luizfelipe/ -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
Sure, go ahead. Cheers, Dave 2009/4/7 Luiz Felipe luiz.fel...@techmit.com.br: ...glad to read the two of you agreeing. Now David, may I use that photo of yours as desktop background for a while? I tried to laugh quietly but my co-workers perceived the tears in my eyes and I had to show them the thread. They also would like to use the photo as background for a while... LF David Savage escreveu: This is true. 2009/4/7 JC OConnell hifis...@gate.net: Its important to remember, that while good technique cant improve a bad image, bad technique CAN destroy a good image. Technique isnt everything, but it doesnt hurt to get it right. JC O'Connell hifis...@gate.net -Original Message- From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of David Savage Sent: Tuesday, April 07, 2009 9:28 AM To: Pentax-Discuss Mail List Subject: Re: Trading resolution for depth of field 2009/4/7 frank theriault knarftheria...@gmail.com: But you can bang my head with all the numbers and theories you want, until I go do it over and over, I'm not going to get it. Some people like the theory behind things, and that's fine, too. But we can't forget what the underlying theory is about: going out and taking photos! Amen! All also add that there thousands upon thousand of technically competent, but mind numbingly boring, photos on the inter web. I know, I have added quite a few to the technically competent, but mediocre, pool myself. DS -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
Oh I informed the model of your request this was her reply: OH MAN I take that as a f*king compliment!! You've helped brighten someone's day. :-) Cheers, Dave 2009/4/7 Luiz Felipe luiz.fel...@techmit.com.br: ...glad to read the two of you agreeing. Now David, may I use that photo of yours as desktop background for a while? I tried to laugh quietly but my co-workers perceived the tears in my eyes and I had to show them the thread. They also would like to use the photo as background for a while... LF -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
David Savage wrote: I remotly controlled it too. The Jedi mind trick is an amazing thing. DS yes, it often helps you see the light at the end of the tunnel... -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
...it is... (with all respect, please...) David, you can't possibly imagine the kind of laughter around here on the account of select excerpts the thread AND the photo. Thanks for your (and her) kind permission. :-) LF David Savage escreveu: Oh I informed the model of your request this was her reply: OH MAN I take that as a f*king compliment!! You've helped brighten someone's day. :-) Cheers, Dave 2009/4/7 Luiz Felipe luiz.fel...@techmit.com.br: ...glad to read the two of you agreeing. Now David, may I use that photo of yours as desktop background for a while? I tried to laugh quietly but my co-workers perceived the tears in my eyes and I had to show them the thread. They also would like to use the photo as background for a while... LF -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- Luiz Felipe luiz.felipe at techmit.com.br http://techmit.com.br/luizfelipe/ -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
On Tue, Apr 07, 2009 at 09:28:28PM +0800, David Savage wrote: 2009/4/7 frank theriault knarftheria...@gmail.com: But you can bang my head with all the numbers and theories you want, until I go do it over and over, I'm not going to get it. Some people like the theory behind things, and that's fine, too. But we can't forget what the underlying theory is about: going out and taking photos! Amen! All also add that there thousands upon thousand of technically competent, but mind numbingly boring, photos on the inter web. I know, I have added quite a few to the technically competent, but mediocre, pool myself. I've done quite a few of those, but they aren't nearly as frustrating as the brilliant photos that were ruined because of a technical error, of which I have quite a few. For sufficiently small values of brilliant that is. Also nice shot of the glowing bunghole. did you do that by timing the flash? Or by aiming a mirror? If you did it with a mirror, you might be able to achieve a similar effect by just taping a mirror to the jeans so her hand didn't need to be there. -- The fastest way to get your question answered on the net is to post the wrong answer. Larry Colen l...@red4est.comhttp://www.red4est.com/lrc -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
2009/4/7 Larry Colen l...@red4est.com: On Tue, Apr 07, 2009 at 09:28:28PM +0800, David Savage wrote: 2009/4/7 frank theriault knarftheria...@gmail.com: But you can bang my head with all the numbers and theories you want, until I go do it over and over, I'm not going to get it. Some people like the theory behind things, and that's fine, too. But we can't forget what the underlying theory is about: going out and taking photos! Amen! All also add that there thousands upon thousand of technically competent, but mind numbingly boring, photos on the inter web. I know, I have added quite a few to the technically competent, but mediocre, pool myself. I've done quite a few of those, but they aren't nearly as frustrating as the brilliant photos that were ruined because of a technical error, of which I have quite a few. For sufficiently small values of brilliant that is. Also nice shot of the glowing bunghole. did you do that by timing the flash? Or by aiming a mirror? If you did it with a mirror, you might be able to achieve a similar effect by just taping a mirror to the jeans so her hand didn't need to be there. She's actually holding a flash was just being goofy, struck this pose and wouldn't you know my shutter went off :-) It's one of many shots I took during the lighting test for a group shot. Me the camera were set up on the roof, the on camera flash was in wireless master mode and the flashes that the models were holding were in wireless slave mode (ie the on camera flash triggered the flashes below) Because we were using a mix of Nikon, Canon Minolta flashes, Nkon CLS optical triggers, we couldn't get the to all go off at the same time. The final shot was still fun: http://farm4.static.flickr.com/3650/3406984942_4162539cb9_b.jpg I'm the one in red on the left with the radio shutter release in hand :-) :-) DS -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
On Tue, Apr 07, 2009 at 09:32:48PM +0800, David Savage wrote: 2009/4/7 Matthew Hunt m...@pobox.com: On Tue, Apr 7, 2009 at 9:28 AM, David Savage ozsav...@gmail.com wrote: I know, I have added quite a few to the technically competent, but mediocre, pool myself. Wow, Flickr really does have a pool for everything. LOL Here's my latest boring photo: http://farm4.static.flickr.com/3319/3420399349_fc22fbab94_o.jpg Yes, since you ask - I *do* think the sun shines out of ... :-) -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
Can we watch the language on list, SOMETIMES? Thanks. - Warning: I am now filtering my email, so you may be censored. **Worried about job security? Check out the 5 safest jobs in a recession. (http://jobs.aol.com/gallery/growing-job-industries?ncid=emlcntuscare0003) -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
David Savage wrote: http://farm4.static.flickr.com/3650/3406984942_4162539cb9_b.jpg I'm the one in red on the left with the radio shutter release in hand :-) Casual Friday in Australia, huh? -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
2009/4/7 Matthew Hunt m...@pobox.com: On Tue, Apr 7, 2009 at 9:28 AM, David Savage ozsav...@gmail.com wrote: I know, I have added quite a few to the technically competent, but mediocre, pool myself. Wow, Flickr really does have a pool for everything. LOL Here's my latest boring photo: http://farm4.static.flickr.com/3319/3420399349_fc22fbab94_o.jpg :-) DS -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
RE: Trading resolution for depth of field
Sir, MY burden of proof is no greater than yours. If you cant provide any reliable proof that my contention is not true, then your word is no better than mine. I dont need any more proof to support my contention than you need to support yours. This is very simple. DOF is all about magnfication and f-stop. I did supply the formula, relative DOF = F-stop number/MAGNIFICATION. INCREASING F-STOP NUMBER OR DECREASING IMAGE MAGINIFICATION increases the image relative DOF. Conversely, DECREASING THE F-STOP NUMBER OR INCREASING THE MAGNIFICATION decreases the image relative DOF. If you dont believe me, do some experiments. I have, its called about 35 years of practical experience to back up what I have read in theory. This isn't my theory, this is the correct theory that I have read and found to be true over the years. JC O'Connell hifis...@gate.net -Original Message- From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of Bob W Sent: Tuesday, April 07, 2009 3:00 PM To: 'Pentax-Discuss Mail List' Subject: RE: Trading resolution for depth of field The entire thread and original post was all about the relative DOF ( how to increase or decrease DOF in an image relative to ANY reference DOF ). But your claims regarding relative DOF are only valid if the image format (film size, crop factor, whatever you want to call it) is constant. A change in format leads to a change in allowable CoC, which you're dropping on the floor. If you dispute that the allowable CoC is different for different formats, then you are the one who is claiming there's an absolute DOF. === NO NO NO NO, My post is ALL INCLUSIVE. The only thing that affects (increases or decreases) the image DOF is : (the image magnification in-camera) (f-stop used). Format, crop factors, COC, print size, etc, blah blah blah have ZERO effect on DOF. That is the common myth I am trying to dispell. Its all about image magnification and f-stop and THATS IT. Changing the format, film size, COC means nothing..ONLY changes to the image magnification and f-stop change the DOF. You seem very certain about this, but you won't provide us with any objective criteria, such as a formula, by which the people who disagree with you can come to any conclusion. Why not? Why don't you provide us with some evidence, then we'll shut up about it? Give us a depth of field formula in which all the terms are constant, except for image magnification in camera and f-stop, and in which viewing distance and coc have ZERO effect. Go on, be a sport. Bob -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
At least it's not Godders and I this time ;-) -Adam On Tue, Apr 7, 2009 at 2:30 PM, Joseph McAllister pentax...@mac.com wrote: Bzzz. On Apr 7, 2009, at 07:06 , JC OConnell wrote: NO NO NO NO, My post is ALL INCLUSIVE. The only thing that affects (increases or decreases) the image DOF is : (the image magnification in-camera) (f-stop used). Format, crop factors, COC, print size, etc, blah blah blah have ZERO effect on DOF. That is the common myth I am trying to dispell. Its all about image magnification and f-stop and THATS IT. Changing the format, film size, COC means nothing..ONLY changes to the image magnification and f-stop change the DOF. Joseph McAllister Lots of gear, not much time http://gallery.me.com/jomac http://web.me.com/jomac/show.me/Blog/Blog.html -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- M. Adam Maas http://www.mawz.ca Explorations of the City Around Us. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
Kenneth Waller http://www.tinyurl.com/272u2f - Original Message - From: Cotty cotty...@mac.com Subject: Re: Trading resolution for depth of field On 7/4/09, Paul Stenquist, discombobulated, unleashed: Let it go. Mark Mark ! Just 'Mark', Mark. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
RE: Trading resolution for depth of field
sharpness has to be defined to define a particular DOF. But when you want to increase or decrease DOF, the whole sharpness/COC thing washes out, only camera f-stops and camera image magnification changes get you there. Im not buying into the argument that if you make anything tiny enough the image DOF is increased or if you make it the size of a billboard the DOF is reduced. Its not, the definition I have been using since the beginnning of thread is that image DOF is all relative, not absolute, and its the relative sharpness of the out of focus planes that can only be changed with mag/fstop. Print size doesnt affect that. JC O'Connell hifis...@gate.net -Original Message- From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of Matthew Hunt Sent: Tuesday, April 07, 2009 3:19 PM To: Pentax-Discuss Mail List Subject: Re: Trading resolution for depth of field On Tue, Apr 7, 2009 at 3:14 PM, JC OConnell hifis...@gate.net wrote: Smaller prints dont have more DOF, they're just harder to see clearly! And that's what determines depth of field: The appearance of sharpness. Every derivation of DOF begins with that criterion. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
Kenneth Waller http://www.tinyurl.com/272u2f - Original Message - From: Paul Stenquist pnstenqu...@comcast.net Subject: Re: Trading resolution for depth of field On Apr 7, 2009, at 3:06 PM, Cotty wrote: On 7/4/09, Luiz Felipe, discombobulated, unleashed: ...glad to read the two of you agreeing. Now David, may I use that photo of yours as desktop background for a while? I tried to laugh quietly but my co-workers perceived the tears in my eyes and I had to show them the thread. They also would like to use the photo as background for a while... It will brighten up the orifice for sure. -- Unfortunately, everyone will get behind in their work. Reminds me of the butcher that backed into a meat grinder. Cheers, Cotty ___/\__ || (O) | People, Places, Pastiche ||=|http://www.cottysnaps.com _ -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
RE: Trading resolution for depth of field
Sir, MY burden of proof is no greater than yours. If you cant provide any reliable proof that my contention is not true, then your word is no better than mine. You haven't supplied us with anything that is falsifiable. All you've given us is unsupported assertions. I dont need any more proof to support my contention than you need to support yours. I've provided you with definitions of terms, a mathematical formula and a published reference. Others have pointed you to definitions and formulae which state the same thing as me, and which also have published references, including references from companies such as Kodak and Zeiss and the leading optical scientists. This is very simple. DOF is all about magnfication and f-stop. I did supply the formula, relative DOF = F-stop number/MAGNIFICATION. INCREASING F-STOP NUMBER OR DECREASING IMAGE MAGINIFICATION increases the image relative DOF. Conversely, DECREASING THE F-STOP NUMBER OR INCREASING THE MAGNIFICATION decreases the image relative DOF. If you dont believe me, do some experiments. I have, its called about 35 years of practical experience to back up what I have read in theory. This isn't my theory, this is the correct theory that I have read and found to be true over the years. I have as much experience of practical photography as you do. I can cite theory, and I can provide references. You cannot provide references, and the formulae you have provided do not include definitions of terms (such as DOF), so they're useless. Give us a respectable reference which supports your claim and these so-called formulae. Bob -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
I think Joe's asleep. I know I am. G On Apr 7, 2009, at 12:32 PM, Adam Maas wrote: At least it's not Godders and I this time ;-) -Adam On Tue, Apr 7, 2009 at 2:30 PM, Joseph McAllister pentax...@mac.com wrote: B zzz . -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
RE: Trading resolution for depth of field
How do you calculate your depth of sleep? I think Joe's asleep. I know I am. G On Apr 7, 2009, at 12:32 PM, Adam Maas wrote: At least it's not Godders and I this time ;-) -Adam On Tue, Apr 7, 2009 at 2:30 PM, Joseph McAllister pentax...@mac.com wrote: B zz zz zz zz zz zz zz zz zz zz zz zz zz zz zzz zz zz zz zz zz zz. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
It's entirely dependent on how many weeks into the semester I am. -Adam On Tue, Apr 7, 2009 at 3:49 PM, Bob W p...@web-options.com wrote: How do you calculate your depth of sleep? I think Joe's asleep. I know I am. G On Apr 7, 2009, at 12:32 PM, Adam Maas wrote: At least it's not Godders and I this time ;-) -Adam On Tue, Apr 7, 2009 at 2:30 PM, Joseph McAllister pentax...@mac.com wrote: B zz zz zz zz zz zz zz zz zz zz zz zz zz zz zzz zz zz zz zz zz zz. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- M. Adam Maas http://www.mawz.ca Explorations of the City Around Us. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
RE: Trading resolution for depth of field
I already stated you can choose ANY reference you want ( a particular COC for example) it doesnt matter, if you want to increase or decrease DOF, regardless of your reference, only image mag/f-stop can CHANGE it. I think what your trying to do is define DOF absolutely, via a maximum COC for example. This is fine if you know and understand that concept. But changing your COC size only changes the way you MEASURE the DOF, it doesnt change the actual DOF. IF if WANT more or less DOF it does not matter how you define/reference it, only MAG/FSTOP changes will increase/decrease the DOF ***COMPARED TO YOUR REFERENCE, WHATEVER YOU CHOOSE*** All the other varibles cancel out and your left with only MAG and F-STOP to increase/decrease DOF. JC O'Connell hifis...@gate.net -Original Message- From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of Bob W Sent: Tuesday, April 07, 2009 3:41 PM To: 'Pentax-Discuss Mail List' Subject: RE: Trading resolution for depth of field Sir, MY burden of proof is no greater than yours. If you cant provide any reliable proof that my contention is not true, then your word is no better than mine. You haven't supplied us with anything that is falsifiable. All you've given us is unsupported assertions. I dont need any more proof to support my contention than you need to support yours. I've provided you with definitions of terms, a mathematical formula and a published reference. Others have pointed you to definitions and formulae which state the same thing as me, and which also have published references, including references from companies such as Kodak and Zeiss and the leading optical scientists. This is very simple. DOF is all about magnfication and f-stop. I did supply the formula, relative DOF = F-stop number/MAGNIFICATION. INCREASING F-STOP NUMBER OR DECREASING IMAGE MAGINIFICATION increases the image relative DOF. Conversely, DECREASING THE F-STOP NUMBER OR INCREASING THE MAGNIFICATION decreases the image relative DOF. If you dont believe me, do some experiments. I have, its called about 35 years of practical experience to back up what I have read in theory. This isn't my theory, this is the correct theory that I have read and found to be true over the years. I have as much experience of practical photography as you do. I can cite theory, and I can provide references. You cannot provide references, and the formulae you have provided do not include definitions of terms (such as DOF), so they're useless. Give us a respectable reference which supports your claim and these so-called formulae. Bob -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
Kenneth Waller http://www.tinyurl.com/272u2f - Original Message - From: Luiz Felipe luiz.fel...@techmit.com.br Subject: Re: Trading resolution for depth of field ...there IS a light at the end... ...its the headlight of the oncoming locomotive. LF Doug Brewer escreveu: David Savage wrote: 2009/4/7 Matthew Hunt m...@pobox.com: On Tue, Apr 7, 2009 at 9:28 AM, David Savage ozsav...@gmail.com wrote: I know, I have added quite a few to the technically competent, but mediocre, pool myself. Wow, Flickr really does have a pool for everything. LOL Here's my latest boring photo: http://farm4.static.flickr.com/3319/3420399349_fc22fbab94_o.jpg :-) DS cool. she flashed you. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
RE: Trading resolution for depth of field
Youre nitpicking my terminology but I can tell you with absolute certainty that what I have said is correct. To increase or decrease DOF you can only do two things: change the f-stop or the in camera magnification. All else is futile because they dont change the DOF one iota. JC O'Connell hifis...@gate.net -Original Message- From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of Joseph McAllister Sent: Tuesday, April 07, 2009 2:19 PM To: Pentax-Discuss Mail List Subject: Re: Trading resolution for depth of field Problems On Apr 7, 2009, at 06:17 , JC OConnell wrote: I don't agree with that terminology, it's his not mine. Primary non-scientific statement indicating prejudicial thought. DOF is relative sharpness Another indication of slurred thought from one who espouses pointillist correctness. of foreground and background objects in an image compared to the objects in the plane of focus. ( just my working terminology FWIW). And an admission that what JCO thinks or does only relates to JCO. The rest of us can go on about our business of taking pictures. Joseph McAllister Lots of gear, not much time http://gallery.me.com/jomac http://web.me.com/jomac/show.me/Blog/Blog.html -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
RE: Trading resolution for depth of field
this needs comment, the Depth of field article is riddled with common erroeous non-factual nonsense ( like format affecting DOF, it doesnt, but magnification does.) When shooting say, near 1:4, it doesnt matter if the format is aps digital or 4x5 film, the DOF is the same. At any given magnification, changing format does NOT effect DOF, it only affects AOV. The COC thing is simply how you MEASURE perceived depth of field, no matter what COC or print size you choose, it doesnt CHANGE the actual image DOF, only magnification and f-stop changes affect the image DOF. This is all based on the simple definition that DOF is the relative sharpness of the out of focus planes... JC O'Connell hifis...@gate.net -Original Message- From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of Joseph McAllister Sent: Tuesday, April 07, 2009 2:07 PM To: Pentax-Discuss Mail List Subject: Re: Trading resolution for depth of field Others, wiser than we, have already discussed this to conclusions. http://en.wikipedia.org/wiki/Circle_of_confusion http://en.wikipedia.org/wiki/Depth_of_Field Unless the changes made yesterday evening to the DoF listing were mischievous PDMLrs. :-) On Apr 7, 2009, at 05:57 , Cory Papenfuss wrote: On Tue, 7 Apr 2009, Paul Stenquist wrote: This is a simple issue. Bob is speaking of perceived depth of filed on a viewed print. JCO is speaking of critical depth of field in respect to the ability of a given lens to resolve detail. Both are correct, but each is discussing an entirely different matter. Let it go. ... but as I'm sure we will discover, only one is correct. ;-) Joseph McAllister Pentaxian http://gallery.me.com/jomac http://web.me.com/jomac/show.me/Blog/Blog.html -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
Circle of drool in the morning On Apr 7, 2009, at 12:49 , Bob W wrote: How do you calculate your depth of sleep? I think Joe's asleep. I know I am. G On Apr 7, 2009, at 12:32 PM, Adam Maas wrote: At least it's not Godders and I this time ;-) -Adam On Tue, Apr 7, 2009 at 2:30 PM, Joseph McAllister pentax...@mac.com wrote: B zz zz zz zz zz zz zz zz zz zz zz zz zz zz zzz zz zz zz zz zz zz. Joseph McAllister pentax...@mac.com http://gallery.me.com/jomac http://web.me.com/jomac/show.me/Blog/Blog.html -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
The capitalization percentage is rising, folks. You may wish to step back a bit On Apr 7, 2009, at 12:53 , JC OConnell wrote: I already stated you can choose ANY reference you want ( a particular COC for example) it doesnt matter, if you want to increase or decrease DOF, regardless of your reference, only image mag/f-stop can CHANGE it. I think what your trying to do is define DOF absolutely, via a maximum COC for example. This is fine if you know and understand that concept. But changing your COC size only changes the way you MEASURE the DOF, it doesnt change the actual DOF. IF if WANT more or less DOF it does not matter how you define/reference it, only MAG/FSTOP changes will increase/decrease the DOF ***COMPARED TO YOUR REFERENCE, WHATEVER YOU CHOOSE*** All the other varibles cancel out and your left with only MAG and F-STOP to increase/decrease DOF. Joseph McAllister pentax...@mac.com http://gallery.me.com/jomac http://web.me.com/jomac/show.me/Blog/Blog.html -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field - Wait!
I think I've got it! The Depth of Field is anything in an image that is not Bokeh! On Apr 7, 2009, at 13:05 , Joseph McAllister wrote: The capitalization percentage is rising, folks. You may wish to step back a bit On Apr 7, 2009, at 12:53 , JC OConnell wrote: I already stated you can choose ANY reference you want ( a particular COC for example) it doesnt matter, if you want to increase or decrease DOF, regardless of your reference, only image mag/f-stop can CHANGE it. I think what your trying to do is define DOF absolutely, via a maximum COC for example. This is fine if you know and understand that concept. But changing your COC size only changes the way you MEASURE the DOF, it doesnt change the actual DOF. IF if WANT more or less DOF it does not matter how you define/reference it, only MAG/FSTOP changes will increase/decrease the DOF ***COMPARED TO YOUR REFERENCE, WHATEVER YOU CHOOSE*** All the other varibles cancel out and your left with only MAG and F-STOP to increase/decrease DOF. Joseph McAllister pentax...@mac.com “If I could tell the story in words, I wouldn’t need to lug a camera.” –Lewis Hine -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
On Apr 7, 2009, at 06:32 , David Savage wrote: 2009/4/7 Matthew Hunt m...@pobox.com: On Tue, Apr 7, 2009 at 9:28 AM, David Savage ozsav...@gmail.com wrote: I know, I have added quite a few to the technically competent, but mediocre, pool myself. Wow, Flickr really does have a pool for everything. LOL Here's my latest boring photo: http://farm4.static.flickr.com/3319/3420399349_fc22fbab94_o.jpg :-) Wow! Nice photo Dave. Good composition, color. I like the way you've balanced the small orange rock in the upper left hand edge with the right foot of the idiot with the uncontrolled highlight up his ass. Superb! :-) Joseph McAllister Pentaxian http://gallery.me.com/jomac http://web.me.com/jomac/show.me/Blog/Blog.html -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
A true flasher ! Kenneth Waller http://www.tinyurl.com/272u2f - Original Message - From: David Savage ozsav...@gmail.com Subject: Re: Trading resolution for depth of field 2009/4/7 Matthew Hunt m...@pobox.com: On Tue, Apr 7, 2009 at 9:28 AM, David Savage ozsav...@gmail.com wrote: I know, I have added quite a few to the technically competent, but mediocre, pool myself. Wow, Flickr really does have a pool for everything. LOL Here's my latest boring photo: http://farm4.static.flickr.com/3319/3420399349_fc22fbab94_o.jpg :-) DS -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
On Tue, Apr 7, 2009 at 3:14 PM, JC OConnell hifis...@gate.net wrote: Smaller prints dont have more DOF, they're just harder to see clearly! And that's what determines depth of field: The appearance of sharpness. Every derivation of DOF begins with that criterion. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
It is very simple. Want more? use big opening. Want less? use little opening. Done. KISS rocks. ]'-) G On Apr 7, 2009, at 12:49 PM, Bob W wrote: How do you calculate your depth of sleep? I think Joe's asleep. I know I am. G On Apr 7, 2009, at 12:32 PM, Adam Maas wrote: At least it's not Godders and I this time ;-) -Adam On Tue, Apr 7, 2009 at 2:30 PM, Joseph McAllister pentax...@mac.com wrote: B zz zz zz zz zz zz zz zz zz zz zz zz zz zz zzz zz zz zz zz zz zz. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
On Tue, Apr 07, 2009 at 11:25:04AM -0700, Joseph McAllister wrote: Here's my latest boring photo: http://farm4.static.flickr.com/3319/3420399349_fc22fbab94_o.jpg :-) Wow! Nice photo Dave. Good composition, color. I like the way you've balanced the small orange rock in the upper left hand edge with the right foot of the idiot with the uncontrolled highlight up his ass. That looks like *her* ass to me. -- The fastest way to get your question answered on the net is to post the wrong answer. Larry Colen l...@red4est.comhttp://www.red4est.com/lrc -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
On Apr 7, 2009, at 3:06 PM, Cotty wrote: On 7/4/09, Luiz Felipe, discombobulated, unleashed: ...glad to read the two of you agreeing. Now David, may I use that photo of yours as desktop background for a while? I tried to laugh quietly but my co-workers perceived the tears in my eyes and I had to show them the thread. They also would like to use the photo as background for a while... It will brighten up the orifice for sure. -- Unfortunately, everyone will get behind in their work. Cheers, Cotty ___/\__ || (O) | People, Places, Pastiche ||=|http://www.cottysnaps.com _ -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
My apologies to the young lady. I had not seen enough points of interest to make a determination. On Apr 7, 2009, at 11:31 , Larry Colen wrote: On Tue, Apr 07, 2009 at 11:25:04AM -0700, Joseph McAllister wrote: Here's my latest boring photo: http://farm4.static.flickr.com/3319/3420399349_fc22fbab94_o.jpg :-) Wow! Nice photo Dave. Good composition, color. I like the way you've balanced the small orange rock in the upper left hand edge with the right foot of the idiot with the uncontrolled highlight up his ass. That looks like *her* ass to me. Joseph McAllister Lots of gear, not much time http://gallery.me.com/jomac http://web.me.com/jomac/show.me/Blog/Blog.html -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
On 7/4/09, Paul Stenquist, discombobulated, unleashed: Let it go. Mark -- Cheers, Cotty ___/\__ || (O) | People, Places, Pastiche ||=|http://www.cottysnaps.com _ -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
On Tue, Apr 07, 2009 at 02:41:08PM -0400, JC OConnell wrote: The COC thing is simply how you MEASURE perceived depth of field, no matter what COC or print size you choose, it I see. So if I don't care whether something is out of focus as long as it looks like it is in focus, then I can use the aforementioned math? -- The fastest way to get your question answered on the net is to post the wrong answer. Larry Colen l...@red4est.comhttp://www.red4est.com/lrc -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
Bzzz . On Apr 7, 2009, at 07:06 , JC OConnell wrote: NO NO NO NO, My post is ALL INCLUSIVE. The only thing that affects (increases or decreases) the image DOF is : (the image magnification in-camera) (f-stop used). Format, crop factors, COC, print size, etc, blah blah blah have ZERO effect on DOF. That is the common myth I am trying to dispell. Its all about image magnification and f-stop and THATS IT. Changing the format, film size, COC means nothing..ONLY changes to the image magnification and f-stop change the DOF. Joseph McAllister Lots of gear, not much time http://gallery.me.com/jomac http://web.me.com/jomac/show.me/Blog/Blog.html -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
RE: Trading resolution for depth of field
The entire thread and original post was all about the relative DOF ( how to increase or decrease DOF in an image relative to ANY reference DOF ). But your claims regarding relative DOF are only valid if the image format (film size, crop factor, whatever you want to call it) is constant. A change in format leads to a change in allowable CoC, which you're dropping on the floor. If you dispute that the allowable CoC is different for different formats, then you are the one who is claiming there's an absolute DOF. === NO NO NO NO, My post is ALL INCLUSIVE. The only thing that affects (increases or decreases) the image DOF is : (the image magnification in-camera) (f-stop used). Format, crop factors, COC, print size, etc, blah blah blah have ZERO effect on DOF. That is the common myth I am trying to dispell. Its all about image magnification and f-stop and THATS IT. Changing the format, film size, COC means nothing..ONLY changes to the image magnification and f-stop change the DOF. You seem very certain about this, but you won't provide us with any objective criteria, such as a formula, by which the people who disagree with you can come to any conclusion. Why not? Why don't you provide us with some evidence, then we'll shut up about it? Give us a depth of field formula in which all the terms are constant, except for image magnification in camera and f-stop, and in which viewing distance and coc have ZERO effect. Go on, be a sport. Bob -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field - Wait!
On Tue, Apr 7, 2009 at 4:07 PM, Joseph McAllister pentax...@mac.com wrote: The Depth of Field is anything in an image that is not Bokeh! But the question is, how much is there? Not much, or bokehtloads? -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
...now you broke my heart... Ken Waller escreveu: Kenneth Waller http://www.tinyurl.com/272u2f - Original Message - From: Luiz Felipe luiz.fel...@techmit.com.br Subject: Re: Trading resolution for depth of field ...there IS a light at the end... ...its the headlight of the oncoming locomotive. LF -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
On 7/4/09, Godfrey DiGiorgi, discombobulated, unleashed: Want more? use big opening. Want less? use little opening. Done. Godfrey, please. A little more decorum. -- Cheers, Cotty ___/\__ || (O) | People, Places, Pastiche ||=|http://www.cottysnaps.com _ -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
You may say that, but there are at least 4 using said picture as desktop background so far... permission granted and everything else. Did I say lately how I love this list??? LF Joseph McAllister escreveu: My apologies to the young lady. I had not seen enough points of interest to make a determination. On Apr 7, 2009, at 11:31 , Larry Colen wrote: On Tue, Apr 07, 2009 at 11:25:04AM -0700, Joseph McAllister wrote: Here's my latest boring photo: http://farm4.static.flickr.com/3319/3420399349_fc22fbab94_o.jpg :-) Wow! Nice photo Dave. Good composition, color. I like the way you've balanced the small orange rock in the upper left hand edge with the right foot of the idiot with the uncontrolled highlight up his ass. That looks like *her* ass to me. Joseph McAllister Lots of gear, not much time http://gallery.me.com/jomac http://web.me.com/jomac/show.me/Blog/Blog.html -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- Luiz Felipe luiz.felipe at techmit.com.br http://techmit.com.br/luizfelipe/ -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
Well, I don't like them that much - all those masks, fireworks... Make mine Led Zep. Godfrey DiGiorgi escreveu: It is very simple. snip KISS rocks. ]'-) G -- Luiz Felipe luiz.felipe at techmit.com.br http://techmit.com.br/luizfelipe/ -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
On Apr 7, 2009, at 11:51 , Larry Colen wrote: On Tue, Apr 07, 2009 at 02:41:08PM -0400, JC OConnell wrote: The COC thing is simply how you MEASURE perceived depth of field, no matter what COC or print size you choose, it I see. So if I don't care whether something is out of focus as long as it looks like it is in focus, then I can use the aforementioned math? Of course! We all have many more 4 x 6 prints that are sharp vs the 11 x 14 version. That's my theory behind the thousands of dog photos in my gallery. 95% of them are not critically sharp (though it's getting better now that the sun is out) but I count on the dog owners to have smaller screens than I, and to only print 4 x 6 from the images they download. Besides, it's their dog, it's free, so it must be good. (does away with all the wedding photo terrors) Joseph McAllister pentax...@mac.com http://gallery.me.com/jomac http://web.me.com/jomac/show.me/Blog/Blog.html -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field - Wait!
On Tue, Apr 07, 2009 at 01:07:35PM -0700, Joseph McAllister wrote: I think I've got it! The Depth of Field is anything in an image that is not Bokeh! Now *this* is a Speckable quote. -- The fastest way to get your question answered on the net is to post the wrong answer. Larry Colen l...@red4est.comhttp://www.red4est.com/lrc -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
On Tue, Apr 07, 2009 at 01:11:02PM -0700, Godfrey DiGiorgi wrote: It is very simple. Want more? use big opening. Want less? use little opening. Done. KISS rocks. ]'-) Yeah, but you seem to be KISSing the wrong end. A smaller opening gives more depth of field, that's why a pinhole camera gives a sharper image than putting a sheet behind your front door. -- The fastest way to get your question answered on the net is to post the wrong answer. Larry Colen l...@red4est.comhttp://www.red4est.com/lrc -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
On Apr 7, 2009, at 1:41 PM, Cotty wrote: On 7/4/09, Godfrey DiGiorgi, discombobulated, unleashed: Want more? use big opening. Want less? use little opening. Done. Godfrey, please. A little more decorum. What have you done with Cotty? G -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
On Apr 7, 2009, at 2:06 PM, Larry Colen wrote: On Tue, Apr 07, 2009 at 01:11:02PM -0700, Godfrey DiGiorgi wrote: It is very simple. Want more? use big opening. Want less? use little opening. Done. KISS rocks. ]'-) Yeah, but you seem to be KISSing the wrong end. A smaller opening gives more depth of field, that's why a pinhole camera gives a sharper image than putting a sheet behind your front door. We were speaking of depth of sleep. Depth of field is the reverse. G -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
On Tue, Apr 7, 2009 at 5:14 PM, Godfrey DiGiorgi godd...@mac.com wrote: We were speaking of depth of sleep. Depth of field is the reverse. I don't really have anything to say, I just wanted to be the 100th poster on this thread. I don't think I've ever done that before on this list or anywhere else. Thanks for your indulgence. Back to your regular programming. cheers, frank -- Sharpness is a bourgeois concept. -Henri Cartier-Bresson -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field - Wait!
If there's a lot, then not much... It's a formula. On Apr 7, 2009, at 13:33 , Matthew Hunt wrote: On Tue, Apr 7, 2009 at 4:07 PM, Joseph McAllister pentax...@mac.com wrote: The Depth of Field is anything in an image that is not Bokeh! But the question is, how much is there? Not much, or bokehtloads? Joseph McAllister pentax...@mac.com http://gallery.me.com/jomac http://web.me.com/jomac/show.me/Blog/Blog.html -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
Floyd On Apr 7, 2009, at 13:48 , Luiz Felipe wrote: Well, I don't like them that much - all those masks, fireworks... Make mine Led Zep. Godfrey DiGiorgi escreveu: It is very simple. snip KISS rocks. ]'-) G -- Joseph McAllister pentax...@mac.com http://gallery.me.com/jomac http://web.me.com/jomac/show.me/Blog/Blog.html -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
On 7/4/09, frank theriault, discombobulated, unleashed: I don't really have anything to say, I just wanted to be the 100th poster on this thread. Well slap my ass and call me Sally. I want this on a T shirt if it skills me. MARK. -- Cheers, Cotty ___/\__ || (O) | People, Places, Pastiche ||=|http://www.cottysnaps.com _ -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Trading resolution for depth of field
On Tue, Apr 7, 2009 at 5:35 PM, Cotty cotty...@mac.com wrote: On 7/4/09, frank theriault, discombobulated, unleashed: I don't really have anything to say, I just wanted to be the 100th poster on this thread. Well slap my ass and call me Sally. I want this on a T shirt if it skills me. MARK. Geez. I don't think I've ever been quoted on a t-shirt before. How cool would that be? cheers, he who lives a hollow life -- Sharpness is a bourgeois concept. -Henri Cartier-Bresson -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
