Re: Re: [pinhole-discussion] exposure outdoors using meter
Thanks for that Guillermo, so as understand it it doesn't matter what the shutterspeed is for you meter reading its the f-stop that counts as it will be converted recipricly anyway. i was using paper for this exercise and thought that you set the shutter speed to the iso of the neg material used, and make a light reading from there. Thanks again for the info :) > > From: "Guillermo" > Date: Wed, 18 Jul 2001 08:23:39 -0400 > To: > Subject: Re: [pinhole-discussion] exposure outdoors using meter > > > - Original Message - > From: > > > With your info i got off your website, the sunny16 + iso exposure rule, > > when using a meter do you use the meter reading and the iso=shutterspeed to > > calculate your exposure? > > Did you mean "iso+shutterspeed"? if so, here is the answer (BTW, I may > overexplain, my excuses in advance for doing that): > > When I use a meter, I set it for the ISO of the emulsion in use, then I take > a reading and obtain a "pair of exposure values", f/stop+shutter_speed, that > is. Then I translate that pair of exposure values to an equivalent pair for > when the f/stop is the one of my pinhole camera. For instance: My pinhole > camera is f/512, a meter reading gives me f/45 @ 1/30, there are 7 stops > between f/45 and f/512 (45 -> 64,90,128,180,256,360,512), therefore the > equivalent pair of exposures values f/45@1/30 for my pinhole camera would be > f/512 @ (1/30 +7stops). 1/30 +7 stops is equal to doubling the time 7 times > 1/30 -> 1/15, 1/8, 1/4, 1/2, 1, 2, 4secs, my pinhole camera exposure should > then be f/512@4 seconds plus any reciprocity correction needed for the > emulsion in use. > > > I used it to teach a class but had varying results, although i have > > suspitions that the cameras were dodgy. > > I just need a little clarification on this. > > But the ones that did turn out on my camera and one other were as near > > perfect as i could have hoped. > > > > The only way to get consistent results from many cameras is if you have > measured the pinholes of all the cameras in a relatively accurate way, which > in turn allow you to know the f/stop of your cameras. Obviously, pinhole of > all the cameras should be clean, free of burrs and obstructions. > > > Also if you have any info on Pinhole under studio flash conditions i would > > really appretiate it, i had a formula worked out which worked well for my > > camera but had limited success with the others. > > I used > > exposure = difference of stops from meter reading to camera aperture x 1.5 > > If you have any suggestions to improve this, that would be great. > > Here is what the Laws of physics MANDATE: you should give a number of flash > "pops" equal to 2 multiplied by itself a number of times equal to the > difference of stops. For instance, stops of difference = 5, number of > "pops"= 2x2x2x2x2 = 32 pops > And then you will have to give few pops more to compensate for INTERMITTENCY > (sp) EFFECT which for the above example would state: an exposure of 32 pops > of low power flashes (flash-A) is less effective that one single pop of a > flash-B with a power equal 5 times the power of flash-A. > > If shooting negative material, you may obtain printable results for up to 4 > stops of difference when using your formula, but for the more stops of > difference the more unlikely you will. > > Hope it helps, > > Guillermo > > > ___ > Pinhole-Discussion mailing list > Pinhole-Discussion@p at ??? > unsubscribe or change your account at > http://www.???/discussion/ >
[pinhole-discussion] exposure outdoors using meter
Guillermo, With your info i got off your website, the sunny16 + iso exposure rule, when using a meter do you use the meter reading and the iso=shutterspeed to calculate your exposure? I used it to teach a class but had varying results, although i have suspitions that the cameras were dodgy. I just need a little clarification on this. But the ones that did turn out on my camera and one other were as near perfect as i could have hoped. Also if you have any info on Pinhole under studio flash conditions i would really appretiate it, i had a formula worked out which worked well for my camera but had limited success with the others. I used exposure = difference of stops from meter reading to camera aperture x 1.5 If you have any suggestions to improve this, that would be great. Thanks :)
Re: Re: [pinhole-discussion] pin hole and flash
I used this theory to start with, (the difference between f-stops = number of flashes) but i found it to be insufficient. i found that i got good results from multiplying the difference by 1.5. (So; exposure = the difference of meter reading and camera aperture x 1.5) EG; meter = f-64, camera = f-283 'pops' = 18. and also soft boxes are not good you need directed undiffused light this seems to work better. I have to run a workshop on my theories as part of my course so i will get back on the flash formula, and see if it accurate for more than just my camera. thanks for the replys, i'll check out the archives ;) > > From: "William Erickson" > Date: Thu, 5 Jul 2001 09:53:14 -0500 > To: > Subject: Re: [pinhole-discussion] pin hole and flash > > I used flash until I dropped the unit and broke the bulb. You need to meter > the flash, obtain the f stop that will give good exposure with the flash > placed where it is, then calculate how much smaller your aperture is than the > aperture you obtained by metering, then flash it that many times. If the > pinhole is 1/50 the area of the metered aperture, you will need to flash 50 > times to get the same exposure. On the other hand, pinhole is about play, so > just play with it. Try hoding the flash close to areas you want to emphasize, > further fronm the shadow areas, and do trials tom see how many flashes you > need. there's some abut flash in Eric Renners book also. From: Jarrard > To: pinhole-discussion@p at ??? > Sent: Thursday, July 05, 2001 3:51 AM > Subject: [pinhole-discussion] pin hole and flash > > > hello. > Im a photography student in New Zealand, and i am using pinhole photography > as a major part of my projects, together with alternative printing emultions > like callitype etc. > I have been working in the studio using flash and was wondering if anybody > has used this technique and had much success, and if they have and tips they > could share. i have not been able to find any info on using flash with a > pinhole camera anywhere and was hopeing that someone had. > Or if anyone is interested in my work with pinhole in the studio, i've had > some pretty nice results, with a few of the images :) > If anyone knows the best sites to go to for info and such, i would greatly > appertiate it :) > Thanks. > > I used flash until I dropped the unit = and broke the=20 bulb. You need to meter the flash, obtain the f stop that will give good = exposure with the flash placed where it is, then calculate how much = smaller your=20 aperture is than the aperture you obtained by metering, then flash = it that=20 many times. If the pinhole is 1/50 the area of the metered aperture, you = will=20 need to flash 50 times to get the same exposure. On the other hand, = pinhole=20 is about play, so just play with it. Try hoding the flash close to areas = you=20 want to emphasize, further fronm the shadow areas, and do trials tom see = how=20 many flashes you need. there's some abut flash in Eric Renners book = also. =20 From: Jarrard To: pinhole-discussion@p at ???= Sent: Thursday, July 05, 2001 = 3:51=20 AM Subject: [pinhole-discussion] = pin hole=20 and flash hello. Im a photography student in New = Zealand, and i am=20 using pinhole photography as a major part of my projects, together = with=20 alternative printing emultions like callitype etc. I have been working in the studio = using=20 flash and was wondering if anybody has used this technique and = had much=20 success, and if they have and tips they could share. i have not been = able to=20 find any info on using flash with a pinhole camera anywhere and was = hopeing=20 that someone had. Or if anyone is interested in my work = with=20 pinhole in the studio, i've had some pretty nice results, with a few = of the=20 images :) If anyone knows the best sites to go = to for info=20 and such, i would greatly appertiate it :) Thanks.
