Comments on: Why Does “Brightness” Wash Colors to White? http://regex.info/blog/2008-08-06/901 Not a photo blog, but sometimes I play one on TV Fri, 05 Dec 2008 15:44:39 +0000 http://wordpress.org/?v=2.0.12-alpha by: Mike http://regex.info/blog/2008-08-06/901#comment-19213 Thu, 07 Aug 2008 13:47:59 +0000 http://regex.info/blog/2008-08-06/901#comment-19213 From your description, it sounds like the raw data is not clipped. Therefore your experience is probably a result of sRGB gamut clipping rather than any limitation of the camera. Take a look at a 3D comparison of sRGB versus ProPhoto RGB and it's pretty clear that the brightness of sRGB reds are pretty limited. I'm not sure how you propose to get brighter reds than sRGB allows without either clipping the entire flower (it will be as bright as saturated red can look in sRGB, but it will be VERY flat) or by accepting some reduced saturation. The physics just don't seem to allow another option unless you use a wider color space such as Adobe RGB, but considering that you posted for the web I'm assuming that your using sRGB. Personally I like to use local exposure reduction using Lightroom's HSL Color Adjustments so I can bring saturated colors back into gamut without having to do a global adjustment on the whole image. Of course there are probably much more powerful methods available in Photoshop, but I find the results from Lightroom are well enough to my liking. Mike From your description, it sounds like the raw data is not clipped. Therefore your experience is probably a result of sRGB gamut clipping rather than any limitation of the camera. Take a look at a 3D comparison of sRGB versus ProPhoto RGB and it’s pretty clear that the brightness of sRGB reds are pretty limited.

I’m not sure how you propose to get brighter reds than sRGB allows without either clipping the entire flower (it will be as bright as saturated red can look in sRGB, but it will be VERY flat) or by accepting some reduced saturation. The physics just don’t seem to allow another option unless you use a wider color space such as Adobe RGB, but considering that you posted for the web I’m assuming that your using sRGB.

Personally I like to use local exposure reduction using Lightroom’s HSL Color Adjustments so I can bring saturated colors back into gamut without having to do a global adjustment on the whole image. Of course there are probably much more powerful methods available in Photoshop, but I find the results from Lightroom are well enough to my liking.

Mike

]]> by: Kip Cole http://regex.info/blog/2008-08-06/901#comment-19202 Wed, 06 Aug 2008 21:25:38 +0000 http://regex.info/blog/2008-08-06/901#comment-19202 Jeffrey, I'm no colour expert, but I think the limitations are due to RGB colour rather than the profiles themselves. The difficulty being that in RGB color the chroma and luminance data are encoded into each of the colour channels. I suspect that if you edited these images in the LAB colour space (which separate the chroma data from the luminance) you would avoid the "fade to white" problem. Of course you will likely end up with lots of unreal colours too (colours that can't be rendered on screen or printer. Cheers, --Kip Jeffrey, I’m no colour expert, but I think the limitations are due to RGB colour rather than the profiles themselves. The difficulty being that in RGB color the chroma and luminance data are encoded into each of the colour channels.

I suspect that if you edited these images in the LAB colour space (which separate the chroma data from the luminance) you would avoid the “fade to white” problem. Of course you will likely end up with lots of unreal colours too (colours that can’t be rendered on screen or printer.

Cheers, –Kip

]]> by: Jon Van Dalen http://regex.info/blog/2008-08-06/901#comment-19197 Wed, 06 Aug 2008 12:19:43 +0000 http://regex.info/blog/2008-08-06/901#comment-19197 You might try running that flame photo through the new Adobe profiles. Adobe Standard or Nikon Standard might yield different color results. Some of the profiles have color balances that add up to less overall brightness thus preserving some colors that Lightroom's defaults can make white or pale. Not that this solves the problem you are talking about in every sense, but it can be illuminating to see other settings and the effect they have on color and color brightness. I would guess that in order to achieve the maximum tonal ranges and contrast in a proper exposure, digital photos have nowhere to go but white in order to represent the brightest areas of color in high contrast situations. This doesn't happen on film? Or does it? You might try running that flame photo through the new Adobe profiles. Adobe Standard or Nikon Standard might yield different color results. Some of the profiles have color balances that add up to less overall brightness thus preserving some colors that Lightroom’s defaults can make white or pale. Not that this solves the problem you are talking about in every sense, but it can be illuminating to see other settings and the effect they have on color and color brightness.

I would guess that in order to achieve the maximum tonal ranges and contrast in a proper exposure, digital photos have nowhere to go but white in order to represent the brightest areas of color in high contrast situations.

This doesn’t happen on film? Or does it?

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