Re: Interesting effect: drastic change of color on photograph
It's a bit late but my semi calibrated CRT, (Hitachi SuperScan Elite 761*), shows them as blue. I thought it might be the screen being off so I tried it on my laptop as well, and the blue elements are blue there as well. On 6/14/2011 11:03 AM, Igor Roshchin wrote: Hi All! After taking photos at a party, I discovered an interesting effect. It was indoors, with uneven and not very bright light, so, I used a flash bounced from the ceiling, which made the light rather uniform. There were some party items in two colors: green and purple. In all shots, the purple came out as blue. All other colors are close to the original. I tried to play with the color temperature and tint in LR, but I cannot make it without skewing the rest of the colors. http://42graphy.org/snapshots/misc/_IR31001.jpg I suspect, that this particular color (dye) fluoresces from the flush, or something like that. This brought up an interesting discussion question: Imagine a well organized party with color matching of various elements (e.g. wedding, with bride's maids' dresses matching the plates, or whatever). In that case, the flash can change the way colors appear. By itself, it is nothing new - the same color on different surfices can appear differently in different light. But, - it would be a nightmare for the photographer (and the wedding organizer, if that person was in charge for the photographs). This opens up many interesting questions that I've never heard discussed. On one hand the event organizer should be aware of such potential problems, - but I am curious, - how many of them try to see how things look under the flash light? I know that, say, stage directors for theaters/ballet are aware of such issues, - I had a chance of talking with one from a famous Russian ballet troup touring the US some 12 years ago. They had to deal with the variation of the light temperature/color in different cities. Otherwise, slightly blueish tutus (Swan Lake) in a yellowish main stage white light look green. If you have worked with the wedding/event organizers who had dealt with such situations, - I'd be very curious to hear about it. And if you were the photographer, - how did you deal with it? Cheers, Igor -- Where's the Kaboom? There was supposed to be an Earth-shattering Kaboom! --Marvin the Martian. -- 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: Interesting effect: drastic change of color on photograph
On 6/14/2011 18:54, Steven Desjardins wrote: Purple for me too. For me three. -- 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: Interesting effect: drastic change of color on photograph
On 15/06/2011 9:55 AM, Igor Roshchin wrote: Bill, thank you for your story about the wedding problems. So, did you find any solution to it back then? Other than explaining to the customer what went wrong and why, there wasn't much to do WRT salvaging anything. I mentioned that I would be willing to hire a retoucher (at her expense) to fix a few prints which I would then make copy negs of, but she didn't take me up on it. The studio work was fine, and most of the outdoor work was as well. Mostly it was the church and reception pictures that showed problems, and they aren't as important anyway. -- William Robb -- 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: Interesting effect: drastic change of color on photograph
On 14/06/2011 7:25 PM, David Parsons wrote: That's awesome. Do you have any of them scanned? I'd love to show them to a MUA friend. Sadly, no. When I was shooting weddings, never bothered to hold back the negatives. I just shot the job, charged a bit extra for giving up potential residual income and handed the negs off to the customers. With a 50% divorce rate, keeping wedding negatives seemed like a bad business pan compared to selling them when the people were still in love. A wedding I shot many years ago ended up being an epic fail because the bride and bridesmaids ended up pooling their make up resources, and probably used half a dozen different brands of product. They looked gorgeous, but the flash pictures showed all sorts of blotches and zebra stripes where make up brands met each other. -- William Robb -- 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: Interesting effect: drastic change of color on photograph
Thank you, guys for all the responses. I understand how fluorescence can be responsible for the color change. (I mentioned that possibility in my original e-mail.) My question was rather, - how can you deal with that... (if at all). Bill, thank you for your story about the wedding problems. So, did you find any solution to it back then? As for the original photo, its colors, and my various viewing sources, I made some additional observations last night, which got me confused even further. Here are my viewing sources: (1) I have a IPS LCD monitor from Dell (U2410, IIRC), that was (not quite-calibrated but) tuned using the calibration software tool that came with it. It seemed to produce rather accurate colors so far. This gets attached to my laptop. (2) I also have a large old professional series CRT monitor attached to my home desktop. It has been tuned in a manner similar to the described above. It's been providing consistency 1) with the actual object colors, 2) with the colors coming from the Epson R2880, and 3) with the back display of my K-7. (3) I also looked at the photos in question directly on my laptop's screen. (4) Finally, I see how the photos look on the back display of the K-7. Results: Sources (2-4) as labeled above showed the same (bluish) color for the original shot in question http://42graphy.org/snapshots/misc/_IR31001.jpg . Source (1) showed purple color close to the expected one. Also, the greens were less yellow, and hence closer to the original (as seen by a naked eye). On the same monitor, the purple color image for which I sent the link yesterday: http://static.heels.com/img/high_heels_blog/wp-content/uploads/2008/04/purple1.jpg became reddish. The laptop's display (3) color was easily tuned to match those of (1) by bumping up the Hue parameter (from 0 to ~30-33) in the Intel Graphics Properties. (I actually remember doing the same thing previously for the projector used to display photos from the same laptop, - for my photo slide show presentations last Fall.) BUT then, I am confused which of my viewing sources are (close to) calibrated, and which are not. If the source (1) and re-tuned (3) are the (more) correct settings, (because they match the original objects as seen by the naked eye) then I am puzzled by 1) Why the camera's back LCD is not showing these colors, but rather colors that I saw on (2)-(4). 2) If (2) is not calibrated properly, - why the color usually match what I expect, and the printed colors (using calibrated paper profiles). 3) Why the purple poster from the link posted above looks almost red, on (1). I guess, I need some good reliable (i.e. known not to change colors depending on the light) colored photo-target for proper screen calibration. Or I should bite the.. err... buy Spyder 3 or another such calibration device. Speaking of which, - I would appreciate your recommendations for the screen calibration devices/tools and procedures. Thank you, Igor -- 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: Interesting effect: drastic change of color on photograph
PS. Is the back display of the cameras calibrated? And if not, - (how) can one calibrate it? Igor -- 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: Interesting effect: drastic change of color on photograph
William Robb wrote: With a 50% divorce rate, keeping wedding negatives seemed like a bad business pan compared to selling them when the people were still in love. Classic! -- Mark Roberts - Photography Multimedia www.robertstech.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: Interesting effect: drastic change of color on photograph
Igor, K7 and K5 screens can be calibrated if I remember well, at least the K5. 2011/6/15 Igor Roshchin s...@komkon.org: PS. Is the back display of the cameras calibrated? And if not, - (how) can one calibrate it? Igor -- 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. -- Thibault Massart aka Thibouille/Thibs -- Photo: K-7, Sigma 28/1.8 macro, FA50/1.4, DA40Ltd, K30/2.8, DA16-45, DA50-135, DA50-200, 360FGZ KX, MX, SuperA+Motor, Z1, P30 Mamiya C330+80/2.8 Sekonic L-208 FalconEyes TE300D x2 Studio flashes Laptop: Macbook 13 Unibody SnowLeo/Win7 Programing: Delphi 2009 -- 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: Interesting effect: drastic change of color on photograph
Two other considerations - the color of the ceiling you're bouncing the flash off of and the color temperature of the ambient light. A white ceiling may not be the same color as other white ceilings and it may not even be a white ceiling. The bounced flash is going to pick up some color. Even if you use flash to over-power the ambient light, the color temperature of that ambient light will still have some effect. FWIW, the forks plate look kind of a purplish blue on my monitor; blue with a hint of indigo. The plate more so than the forks. From: Igor Roshchin Hi All! After taking photos at a party, I discovered an interesting effect. It was indoors, with uneven and not very bright light, so, I used a flash bounced from the ceiling, which made the light rather uniform. There were some party items in two colors: green and purple. In all shots, the purple came out as blue. All other colors are close to the original. I tried to play with the color temperature and tint in LR, but I cannot make it without skewing the rest of the colors. http://42graphy.org/snapshots/misc/_IR31001.jpg I suspect, that this particular color (dye) fluoresces from the flush, or something like that. This brought up an interesting discussion question: Imagine a well organized party with color matching of various elements (e.g. wedding, with bride's maids' dresses matching the plates, or whatever). In that case, the flash can change the way colors appear. By itself, it is nothing new - the same color on different surfices can appear differently in different light. But, - it would be a nightmare for the photographer (and the wedding organizer, if that person was in charge for the photographs). This opens up many interesting questions that I've never heard discussed. On one hand the event organizer should be aware of such potential problems, - but I am curious, - how many of them try to see how things look under the flash light? I know that, say, stage directors for theaters/ballet are aware of such issues, - I had a chance of talking with one from a famous Russian ballet troup touring the US some 12 years ago. They had to deal with the variation of the light temperature/color in different cities. Otherwise, slightly blueish tutus (Swan Lake) in a yellowish main stage white light look green. If you have worked with the wedding/event organizers who had dealt with such situations, - I'd be very curious to hear about it. And if you were the photographer, - how did you deal with it? Cheers, Igor - No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1382 / Virus Database: 1513/3704 - Release Date: 06/14/11 -- 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: Interesting effect: drastic change of color on photograph
From: Mark Roberts William Robb wrote: Igor, filters aren't all that spectrum specific, and tend to be cut filters, in that they don't pass any spectrum below a particular wavelength (which will vary from filter to filter). UV florescence has been a problem since the dawn of electronic flash. A lot of things reflect a disproportionate amount of UV light. Mr. Robb speaks the truth. And note that fluorescence involves absorbing light of one wavelength (ultraviolet) and re-emitting the energy at *different* wavelengths (in the visible spectrum). Looking at the other photo from the party that Igor posted, I suspect there was a significant amount of blue skylight from the window. The brain has the power to process for that and still detect the colors in the tableware. The camera sensor does not. - No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1382 / Virus Database: 1513/3704 - Release Date: 06/14/11 -- 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.
Interesting effect: drastic change of color on photograph
Hi All! After taking photos at a party, I discovered an interesting effect. It was indoors, with uneven and not very bright light, so, I used a flash bounced from the ceiling, which made the light rather uniform. There were some party items in two colors: green and purple. In all shots, the purple came out as blue. All other colors are close to the original. I tried to play with the color temperature and tint in LR, but I cannot make it without skewing the rest of the colors. http://42graphy.org/snapshots/misc/_IR31001.jpg I suspect, that this particular color (dye) fluoresces from the flush, or something like that. This brought up an interesting discussion question: Imagine a well organized party with color matching of various elements (e.g. wedding, with bride's maids' dresses matching the plates, or whatever). In that case, the flash can change the way colors appear. By itself, it is nothing new - the same color on different surfices can appear differently in different light. But, - it would be a nightmare for the photographer (and the wedding organizer, if that person was in charge for the photographs). This opens up many interesting questions that I've never heard discussed. On one hand the event organizer should be aware of such potential problems, - but I am curious, - how many of them try to see how things look under the flash light? I know that, say, stage directors for theaters/ballet are aware of such issues, - I had a chance of talking with one from a famous Russian ballet troup touring the US some 12 years ago. They had to deal with the variation of the light temperature/color in different cities. Otherwise, slightly blueish tutus (Swan Lake) in a yellowish main stage white light look green. If you have worked with the wedding/event organizers who had dealt with such situations, - I'd be very curious to hear about it. And if you were the photographer, - how did you deal with it? Cheers, Igor -- 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: Interesting effect: drastic change of color on photograph
On 15 June 2011 01:03, Igor Roshchin s...@komkon.org wrote: Hi All! After taking photos at a party, I discovered an interesting effect. It was indoors, with uneven and not very bright light, so, I used a flash bounced from the ceiling, which made the light rather uniform. There were some party items in two colors: green and purple. In all shots, the purple came out as blue. All other colors are close to the original. I tried to play with the color temperature and tint in LR, but I cannot make it without skewing the rest of the colors. http://42graphy.org/snapshots/misc/_IR31001.jpg I suspect, that this particular color (dye) fluoresces from the flush, or something like that. Hi Igor, It may just be your display system as the items show up as purple on my calibrated screen. Cheers, -- Rob Studdert (Digital Image Studio) Tel: +61-418-166-870 UTC +10 Hours Gmail, eBay, Skype, Twitter, Facebook, Picasa: distudio -- 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: Interesting effect: drastic change of color on photograph
Purple for me too. On Tue, Jun 14, 2011 at 11:08 AM, Rob Studdert distudio.p...@gmail.com wrote: On 15 June 2011 01:03, Igor Roshchin s...@komkon.org wrote: Hi All! After taking photos at a party, I discovered an interesting effect. It was indoors, with uneven and not very bright light, so, I used a flash bounced from the ceiling, which made the light rather uniform. There were some party items in two colors: green and purple. In all shots, the purple came out as blue. All other colors are close to the original. I tried to play with the color temperature and tint in LR, but I cannot make it without skewing the rest of the colors. http://42graphy.org/snapshots/misc/_IR31001.jpg I suspect, that this particular color (dye) fluoresces from the flush, or something like that. Hi Igor, It may just be your display system as the items show up as purple on my calibrated screen. Cheers, -- Rob Studdert (Digital Image Studio) Tel: +61-418-166-870 UTC +10 Hours Gmail, eBay, Skype, Twitter, Facebook, Picasa: distudio -- 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. -- Steve Desjardins -- 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: Interesting effect: drastic change of color on photograph
Tue Jun 14 11:08:09 EDT 2011 Rob Studdert wrote: On 15 June 2011 01:03, Igor Roshchin str at komkon.org wrote: Hi All! After taking photos at a party, I discovered an interesting effect. It was indoors, with uneven and not very bright light, so, I used a flash bounced from the ceiling, which made the light rather uniform. There were some party items in two colors: green and purple. In all shots, the purple came out as blue. All other colors are close to the original. I tried to play with the color temperature and tint in LR, but I cannot make it without skewing the rest of the colors. http://42graphy.org/snapshots/misc/_IR31001.jpg I suspect, that this particular color (dye) fluoresces from the flush, or something like that. Hi Igor, It may just be your display system as the items show up as purple on my calibrated screen. Rob, Steven, I am not sure.. Maybe we are talking about different definitions of purple. I am talking about this purple: http://static.heels.com/img/high_heels_blog/wp-content/uploads/2008/04/purple1.jpg As for the colors on my photo, I see them pretty much the same way on the LCD of my K-7, my CRT (calibrated by not with any sensor), and my laptop. On none of them, the color is purple. In this shot, - the forks are more purple (although not to the true color, as seen by eye): http://42graphy.org/snapshots/misc/_IR30992.jpg Note, that the plates and the forks were of the same color, as well as the napkins in the back of the table on this shot. Igor -- 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: Interesting effect: drastic change of color on photograph
Igor, under Lightroom develop module, TSI, tint: adjusting blue and purple made a lot of difference and look more like the colour you linked as reference. I got blue +25 and purple +72. I dunno if this is close enough, but a lot better, at least to me. 2011/6/14 Igor Roshchin s...@komkon.org: Tue Jun 14 11:08:09 EDT 2011 Rob Studdert wrote: On 15 June 2011 01:03, Igor Roshchin str at komkon.org wrote: Hi All! After taking photos at a party, I discovered an interesting effect. It was indoors, with uneven and not very bright light, so, I used a flash bounced from the ceiling, which made the light rather uniform. There were some party items in two colors: green and purple. In all shots, the purple came out as blue. All other colors are close to the original. I tried to play with the color temperature and tint in LR, but I cannot make it without skewing the rest of the colors. http://42graphy.org/snapshots/misc/_IR31001.jpg I suspect, that this particular color (dye) fluoresces from the flush, or something like that. Hi Igor, It may just be your display system as the items show up as purple on my calibrated screen. Rob, Steven, I am not sure.. Maybe we are talking about different definitions of purple. I am talking about this purple: http://static.heels.com/img/high_heels_blog/wp-content/uploads/2008/04/purple1.jpg As for the colors on my photo, I see them pretty much the same way on the LCD of my K-7, my CRT (calibrated by not with any sensor), and my laptop. On none of them, the color is purple. In this shot, - the forks are more purple (although not to the true color, as seen by eye): http://42graphy.org/snapshots/misc/_IR30992.jpg Note, that the plates and the forks were of the same color, as well as the napkins in the back of the table on this shot. Igor -- 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. -- Thibault Massart aka Thibouille/Thibs -- Photo: K-7, Sigma 28/1.8 macro, FA50/1.4, DA40Ltd, K30/2.8, DA16-45, DA50-135, DA50-200, 360FGZ KX, MX, SuperA+Motor, Z1, P30 Mamiya C330+80/2.8 Sekonic L-208 FalconEyes TE300D x2 Studio flashes Laptop: Macbook 13 Unibody SnowLeo/Win7 Programing: Delphi 2009 -- 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: Interesting effect: drastic change of color on photograph
On Tue, Jun 14, 2011 at 11:03:41AM -0400, Igor Roshchin wrote: Hi All! After taking photos at a party, I discovered an interesting effect. It was indoors, with uneven and not very bright light, so, I used a flash bounced from the ceiling, which made the light rather uniform. [ . . . ] I suspect, that this particular color (dye) fluoresces from the flush, or something like that. Quite likely - dyes (or pigments) used to colour plastic items often have significant response to ultra-violet light. Even if they don't fluoresce, the output from a flash can produce quite a bit of UV light, and sensors see further into the UV than does the human eye. You could try using a UV filter on either the camera or the flash. This isn't a problem that's new to the digital age, though. I used to have all sorts of problems with one of the race cars in CART. To the human eye one of the colours on the car was a fairly bright orange, but on one particular film (Portra 400, IIRC) it showed up once or twice as more of a blue/purple colour. That was in sunlight. Basically, there can be problems with any colour where the spectral response is strongly peaked at a few wavelengths, rather than being distributed more evenly across the range. Colour photography only records three (or, sometimes, four) different numbers, and then uses these to produce an image. Most of the time this works well enough, because the filters used mimic the response of the human eye (which, after all, does very much the same kin d of thing) fairly closely. But it's easy enough to find examples where two items which appear identical to one sensor will look very diffferent to another sensor (or even to the original sensor under different lighting conditions). -- 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: Interesting effect: drastic change of color on photograph
On Tue, Jun 14, 2011 at 11:03 AM, Igor Roshchin s...@komkon.org wrote: Hi All! After taking photos at a party, I discovered an interesting effect. It was indoors, with uneven and not very bright light, so, I used a flash bounced from the ceiling, which made the light rather uniform. There were some party items in two colors: green and purple. In all shots, the purple came out as blue. All other colors are close to the original. I tried to play with the color temperature and tint in LR, but I cannot make it without skewing the rest of the colors. I am seeing the purple as blue on my iMac. I have run into this problem with my D200 and SB800 flashes which as far as i';m concerned, produce a better flash shot than my K10-D and AF 360. Dave Dave http://42graphy.org/snapshots/misc/_IR31001.jpg I suspect, that this particular color (dye) fluoresces from the flush, or something like that. This brought up an interesting discussion question: Imagine a well organized party with color matching of various elements (e.g. wedding, with bride's maids' dresses matching the plates, or whatever). In that case, the flash can change the way colors appear. By itself, it is nothing new - the same color on different surfices can appear differently in different light. But, - it would be a nightmare for the photographer (and the wedding organizer, if that person was in charge for the photographs). This opens up many interesting questions that I've never heard discussed. On one hand the event organizer should be aware of such potential problems, - but I am curious, - how many of them try to see how things look under the flash light? I know that, say, stage directors for theaters/ballet are aware of such issues, - I had a chance of talking with one from a famous Russian ballet troup touring the US some 12 years ago. They had to deal with the variation of the light temperature/color in different cities. Otherwise, slightly blueish tutus (Swan Lake) in a yellowish main stage white light look green. If you have worked with the wedding/event organizers who had dealt with such situations, - I'd be very curious to hear about it. And if you were the photographer, - how did you deal with it? Cheers, Igor -- 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. -- Documenting Life in Rural Ontario. www.caughtinmotion.com http://brooksinthecountry.blogspot.com/ York Region, Ontario, Canada -- 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: Interesting effect: drastic change of color on photograph
Tue Jun 14 13:48:28 EDT 2011 John Francis wrote: On Tue, Jun 14, 2011 at 11:03:41AM -0400, Igor Roshchin wrote: Hi All! After taking photos at a party, I discovered an interesting effect. It was indoors, with uneven and not very bright light, so, I used a flash bounced from the ceiling, which made the light rather uniform. [ . . . ] I suspect, that this particular color (dye) fluoresces from the flush, or something like that. Quite likely - dyes (or pigments) used to colour plastic items often have significant response to ultra-violet light. Even if they don't fluoresce, the output from a flash can produce quite a bit of UV light, and sensors see further into the UV than does the human eye. You could try using a UV filter on either the camera or the flash. John, Even though purple might have an mixture of blue/violet with red, I would expect that purple would be farther on the spectrum and closer to the violet part than blue. That would mean that hitting the violet (or UV) part of the spectrum should shift the color toward violet, not toward blue. Tue Jun 14 13:37:34 EDT 2011 Thibouille wrote: Igor, under Lightroom develop module, TSI, tint: adjusting blue and purple made a lot of difference and look more like the colour you linked as reference. I got blue +25 and purple +72. I dunno if this is close enough, but a lot better, at least to me. Indeed, that correction is close to the original color. I am sure, it is possible to recolor most of the photos. What I meant that it was not just the result of a WB setting, but rather a selective shift of a color. It is the first time I've seen such a drastic effect. The only other comparably drastic effect that I've seen would be clothes with reflective elements -- e.g. as in this snapshot: http://bard-cafe.komkon.org/PhotoIgor/East2002/images/DCP_0433.jpg . Sometimes, those can even mess up the exposure: http://bard-cafe.komkon.org/PhotoIgor/East2002/images/DCP_0432.jpg . Tue Jun 14 14:11:20 EDT 2011 David J Brooks wrote: On Tue, Jun 14, 2011 at 11:03 AM, Igor Roshchin str at komkon.org wrote: Hi All! After taking photos at a party, I discovered an interesting effect. It was indoors, with uneven and not very bright light, so, I used a flash bounced from the ceiling, which made the light rather uniform. There were some party items in two colors: green and purple. In all shots, the purple came out as blue. All other colors are close to the original. I tried to play with the color temperature and tint in LR, but I cannot make it without skewing the rest of the colors. I am seeing the purple as blue on my iMac. I have run into this problem with my D200 and SB800 flashes which as far as i';m concerned, produce a better flash shot than my K10-D and AF 360. Dave Dave Double exposure? ;-) There is a pizza chain in TX called Double Dave's doubledaves.com . :-) I am mostly happy how Metz 58 works with my K7. Very often, especially when bouncing light from the ceiling/walls, I set the flash to A setting, and it exposes better than when set to P-TTL. Igor -- 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: Interesting effect: drastic change of color on photograph
On 14/06/2011 12:46 PM, Igor Roshchin wrote: Tue Jun 14 13:48:28 EDT 2011 John Francis wrote: On Tue, Jun 14, 2011 at 11:03:41AM -0400, Igor Roshchin wrote: Hi All! After taking photos at a party, I discovered an interesting effect. It was indoors, with uneven and not very bright light, so, I used a flash bounced from the ceiling, which made the light rather uniform. [ . . . ] I suspect, that this particular color (dye) fluoresces from the flush, or something like that. Quite likely - dyes (or pigments) used to colour plastic items often have significant response to ultra-violet light. Even if they don't fluoresce, the output from a flash can produce quite a bit of UV light, and sensors see further into the UV than does the human eye. You could try using a UV filter on either the camera or the flash. John, Even though purple might have an mixture of blue/violet with red, I would expect that purple would be farther on the spectrum and closer to the violet part than blue. That would mean that hitting the violet (or UV) part of the spectrum should shift the color toward violet, not toward blue. Igor, filters aren't all that spectrum specific, and tend to be cut filters, in that they don't pass any spectrum below a particular wavelength (which will vary from filter to filter). UV florescence has been a problem since the dawn of electronic flash. A lot of things reflect a disproportionate amount of UV light. This is especially true of man made fabric materials (nylon, rayon, satin, and the like and make up. My wife has a lovely emerald green gown that photographs blue with flash, and bluey green under daylight, for example. A wedding I shot many years ago ended up being an epic fail because the bride and bridesmaids ended up pooling their make up resources, and probably used half a dozen different brands of product. They looked gorgeous, but the flash pictures showed all sorts of blotches and zebra stripes where make up brands met each other. -- William Robb -- 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: Interesting effect: drastic change of color on photograph
William Robb wrote: Igor, filters aren't all that spectrum specific, and tend to be cut filters, in that they don't pass any spectrum below a particular wavelength (which will vary from filter to filter). UV florescence has been a problem since the dawn of electronic flash. A lot of things reflect a disproportionate amount of UV light. Mr. Robb speaks the truth. And note that fluorescence involves absorbing light of one wavelength (ultraviolet) and re-emitting the energy at *different* wavelengths (in the visible spectrum). -- Mark Roberts - Photography Multimedia www.robertstech.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: Interesting effect: drastic change of color on photograph
On Jun 14, 2011, at 2:36 PM, Mark Roberts wrote: William Robb wrote: Igor, filters aren't all that spectrum specific, and tend to be cut filters, in that they don't pass any spectrum below a particular wavelength (which will vary from filter to filter). UV florescence has been a problem since the dawn of electronic flash. A lot of things reflect a disproportionate amount of UV light. Mr. Robb speaks the truth. And note that fluorescence involves absorbing light of one wavelength (ultraviolet) and re-emitting the energy at *different* wavelengths (in the visible spectrum). So it may be necessary to put a UV filter over the flash, not over the lens. -- Larry Colen l...@red4est.com sent from i4est -- 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: Interesting effect: drastic change of color on photograph
On Tue, Jun 14, 2011 at 02:46:42PM -0400, Igor Roshchin wrote: Tue Jun 14 13:48:28 EDT 2011 John Francis wrote: On Tue, Jun 14, 2011 at 11:03:41AM -0400, Igor Roshchin wrote: Hi All! After taking photos at a party, I discovered an interesting effect. It was indoors, with uneven and not very bright light, so, I used a flash bounced from the ceiling, which made the light rather uniform. [ . . . ] I suspect, that this particular color (dye) fluoresces from the flush, or something like that. Quite likely - dyes (or pigments) used to colour plastic items often have significant response to ultra-violet light. Even if they don't fluoresce, the output from a flash can produce quite a bit of UV light, and sensors see further into the UV than does the human eye. You could try using a UV filter on either the camera or the flash. John, Even though purple might have an mixture of blue/violet with red, I would expect that purple would be farther on the spectrum and closer to the violet part than blue. That would mean that hitting the violet (or UV) part of the spectrum should shift the color toward violet, not toward blue. The sensor doesn't qualify the light hitting it by the actual wavelength. Some UV light excites the sensor at the blue pixels, registering blue, but gets filtered out of the red pixels. your camera can't tell the difference between a monochromatic blue light and a mixture of blue and UV light that excites the blue sensor, but is blocked by the Bayer filter over the red and green pixels. -- 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: Interesting effect: drastic change of color on photograph
On Jun 14, 2011, at 2:49 PM, John Francis wrote: On Tue, Jun 14, 2011 at 02:46:42PM -0400, Igor Roshchin wrote: Tue Jun 14 13:48:28 EDT 2011 John Francis wrote: On Tue, Jun 14, 2011 at 11:03:41AM -0400, Igor Roshchin wrote: Hi All! The sensor doesn't qualify the light hitting it by the actual wavelength. Some UV light excites the sensor at the blue pixels, registering blue, but gets filtered out of the red pixels. your camera can't tell the difference between a monochromatic blue light and a mixture of blue and UV light that excites the blue sensor, but is blocked by the Bayer filter over the red and green pixels. There's also the question of the display. The evening I shot these photos: http://www.flickr.com/photos/ellarsee/sets/72157626084484859/ When I previewed the shots, all the pictures of my very purple hat looked blue. On my display, the purple in Igor's pictures looks pretty purple, and the forks and plates look pretty close. Is it possible that Igor's display just doesn't have the dynamic range to properly display the purple without tweaking the other colors? -- 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. -- Larry Colen l...@red4est.com sent from i4est -- 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: Interesting effect: drastic change of color on photograph
Igor, Time to check your display's calibration. It's purple to me... Regards, Bob S. On Tue, Jun 14, 2011 at 10:03 AM, Igor Roshchin s...@komkon.org wrote: Hi All! After taking photos at a party, I discovered an interesting effect. It was indoors, with uneven and not very bright light, so, I used a flash bounced from the ceiling, which made the light rather uniform. There were some party items in two colors: green and purple. In all shots, the purple came out as blue. All other colors are close to the original. I tried to play with the color temperature and tint in LR, but I cannot make it without skewing the rest of the colors. http://42graphy.org/snapshots/misc/_IR31001.jpg I suspect, that this particular color (dye) fluoresces from the flush, or something like that. This brought up an interesting discussion question: Imagine a well organized party with color matching of various elements (e.g. wedding, with bride's maids' dresses matching the plates, or whatever). In that case, the flash can change the way colors appear. By itself, it is nothing new - the same color on different surfices can appear differently in different light. But, - it would be a nightmare for the photographer (and the wedding organizer, if that person was in charge for the photographs). This opens up many interesting questions that I've never heard discussed. On one hand the event organizer should be aware of such potential problems, - but I am curious, - how many of them try to see how things look under the flash light? I know that, say, stage directors for theaters/ballet are aware of such issues, - I had a chance of talking with one from a famous Russian ballet troup touring the US some 12 years ago. They had to deal with the variation of the light temperature/color in different cities. Otherwise, slightly blueish tutus (Swan Lake) in a yellowish main stage white light look green. If you have worked with the wedding/event organizers who had dealt with such situations, - I'd be very curious to hear about it. And if you were the photographer, - how did you deal with it? Cheers, Igor -- 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: Interesting effect: drastic change of color on photograph
On 14/06/2011 3:43 PM, Larry Colen wrote: So it may be necessary to put a UV filter over the flash, not over the lens. I noticed a huge improvement in colour fidelity at weddings when I stopped using Vivitar shoe mount flashes on R. Goldberg brackets and started using pro grade Metz flash units that had a UV absorbing filter built into the head. -- William Robb -- 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: Interesting effect: drastic change of color on photograph
That's awesome. Do you have any of them scanned? I'd love to show them to a MUA friend. On Tue, Jun 14, 2011 at 4:40 PM, William Robb anotherdrunken...@gmail.com wrote: On 14/06/2011 12:46 PM, Igor Roshchin wrote: Tue Jun 14 13:48:28 EDT 2011 John Francis wrote: On Tue, Jun 14, 2011 at 11:03:41AM -0400, Igor Roshchin wrote: Hi All! After taking photos at a party, I discovered an interesting effect. It was indoors, with uneven and not very bright light, so, I used a flash bounced from the ceiling, which made the light rather uniform. [ . . . ] I suspect, that this particular color (dye) fluoresces from the flush, or something like that. Quite likely - dyes (or pigments) used to colour plastic items often have significant response to ultra-violet light. Even if they don't fluoresce, the output from a flash can produce quite a bit of UV light, and sensors see further into the UV than does the human eye. You could try using a UV filter on either the camera or the flash. John, Even though purple might have an mixture of blue/violet with red, I would expect that purple would be farther on the spectrum and closer to the violet part than blue. That would mean that hitting the violet (or UV) part of the spectrum should shift the color toward violet, not toward blue. Igor, filters aren't all that spectrum specific, and tend to be cut filters, in that they don't pass any spectrum below a particular wavelength (which will vary from filter to filter). UV florescence has been a problem since the dawn of electronic flash. A lot of things reflect a disproportionate amount of UV light. This is especially true of man made fabric materials (nylon, rayon, satin, and the like and make up. My wife has a lovely emerald green gown that photographs blue with flash, and bluey green under daylight, for example. A wedding I shot many years ago ended up being an epic fail because the bride and bridesmaids ended up pooling their make up resources, and probably used half a dozen different brands of product. They looked gorgeous, but the flash pictures showed all sorts of blotches and zebra stripes where make up brands met each other. -- William Robb -- 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. -- David Parsons Photography http://www.davidparsonsphoto.com Aloha Photographer Photoblog http://alohaphotog.blogspot.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.
