Posted by Kalin Wilson on May 15, 2007 at 12:39 AM
Does anyone know what the rendering intent is in Lightroom when you export to sRGB? I've read about color management in LR. Day to day editing is in ProPhotoRGB with a gamma of 1.0. The histograms are shown in a tailored sRGB. I normally edit in photoshop in ProPhotoRGB 16bit color. However, I've noticed that some of my exports for web posting can suffer from the conversion to sRGB. Of course the question is moot since a rendering intent option isn't given for export, just printing.
The question came up because I wanted to share this photo of Lower Antelope that I've been working with. It prints just the way I want. The oranges have a nice glow but you can see detail and the saturation isn't blown out, IMO. In the web version, the saturation goes a little over the top.
Posted by Kalin Wilson on May 15, 2007 at 12:43 AM
Just for good measure, here is another of my favorites from that trip that I've got printing the way I want. You may remeber this shot from my HDR comparison. For this image, I took Rick's advice and started with the best exposure, the base exposure, and did some very selective blending of the hightlight and shadow exposures.
I've got some others to share but I'll post them on my site rather than clog the bandwidth here. I'll let you know when they're up.
Unfortunately it doesn't matter which rendering intent LR uses for profile conversion on Export, because at this point you can't do anything to change it. (I suspect it's Perceptual; I haven't yet found a definitive answer.)
The main issue is that converting from ProPhoto (or any large color space) into sRGB (or any smaller color space) will always result in some shifts in color; it can't be helped. The only issue is whether these shifts are visually perceptible or undesirable.
In images with heavily saturated oranges and reds you will often see color shifts when converting from ProPhoto to sRGB. In these cases, if you don't like the result from LR, it would be best to perform the conversion in Photoshop instead so you can have some control over the output and a preview of how it will look, and make any necessary adjustments after the conversion.
This issue is a hot topic and I believe near-future releases of LR will offer more controls over color conversions, including soft proofing.
Keep in mind that some images will look better converted using Perceptual while others look better with Relative Colorimetric. This applies for both on-screen and print output.
Just a slight twist on what Nat said - Relative Colorimetric will only remap colors that are out of gamut and will leave all others untouched, so if most or all of the colors in your image exist in sRGB you will not see any color shifts. Perceptual remaps all colors to fit within the target space and retain their relationships - this will practically always produce some color shifts.
Thanks guys. I was hoping maybe someone knew of a control or something in LR that I hadn't found. For the most part I've had pretty good luck getting reasonable sRGB versions of my images for web display either out of the box with LR export or using relative colorimetric in PS for the reasons Guy stated. It's just a little frustrating to have to worry about each conversion and how it will look, but I guess that's the cost of making a good presentation.
I've been watching a lot of the conversations about LR. I think the next version/update will be significant.
I've had the best results using Relative for most prints and Perceptual for most sRGB conversions. This is largely due to the fact that (in addition to the processing that Guy explained) the destination white point is remapped in Relative but not in Perceptual. When printing, I usually want to adjust the white point to compensate for variations in paper white. On for conversions destined for screen only no remapping is necessary.
Guy's point about the effects of Relative vs. Perceptual help illustrate why the effects of profile conversion vary from image to image and depend entirely on how the destination profile relates to the actual color values in the file.
Regardless, you'd be hard-pressed to find a ProPhoto file that came from a 16-bit (actually 12 or 14-bit) digital camera capture and processed into 16-bit ProPhoto that would fit entirely into the sRGB space. (Interestingly, sRGB actually has a wider gamut in the greens than even ProPhoto, though reds will suffer.) That's why there will always be some colors that get remapped to new values in the destination space; it's just a question of if you can see the difference or not.
So I almost always try both Relative and Perceptual, and use the rendering intent that looks the closest to the original.
Anyone seriously interested in the nuts and bolts of digital color should read Real World Color Management by Bruce Frasier et al. It's a heady read but really thoroughly explains how this all works.
An interesting side note - one of the coolest features of Lightroom is the modular architecture. It's expected that a lot of the new functionality (like Photoshop plug-ins) will be implemented as standalone, third-party modules that will be accessed from the module picker and/or the panels. To me, this holds a lot of promise: applications within an application that essentially could do any kind of image processing the software developer envisions.
I haven't come across any upgrade/ discount codes for CS3 yet. So far the best deals I have seen are for Photoshop CS3 Extended at $289 at the Educational price (Standalone, and not the full CS3 Suite... but does include Bridge etc.).
If you are a student or a teacher with some kind of insitutional ID, or know someone who is, and don't have an eligible version to upgrade from, this is the cheapest way to the full version of PS CS3. Some Google searches for academic software discounts will turn up the major players.
I think for most serious photographers Extended will be worth the extra $$$.
Discussion
7 repliesThe question came up because I wanted to share this photo of Lower Antelope that I've been working with. It prints just the way I want. The oranges have a nice glow but you can see detail and the saturation isn't blown out, IMO. In the web version, the saturation goes a little over the top.
I've got some others to share but I'll post them on my site rather than clog the bandwidth here. I'll let you know when they're up.
Thanks for looking!
~Kalin
Beautiful photographs!
Unfortunately it doesn't matter which rendering intent LR uses for profile conversion on Export, because at this point you can't do anything to change it. (I suspect it's Perceptual; I haven't yet found a definitive answer.)
The main issue is that converting from ProPhoto (or any large color space) into sRGB (or any smaller color space) will always result in some shifts in color; it can't be helped. The only issue is whether these shifts are visually perceptible or undesirable.
In images with heavily saturated oranges and reds you will often see color shifts when converting from ProPhoto to sRGB. In these cases, if you don't like the result from LR, it would be best to perform the conversion in Photoshop instead so you can have some control over the output and a preview of how it will look, and make any necessary adjustments after the conversion.
This issue is a hot topic and I believe near-future releases of LR will offer more controls over color conversions, including soft proofing.
Keep in mind that some images will look better converted using Perceptual while others look better with Relative Colorimetric. This applies for both on-screen and print output.
Guy
I've been watching a lot of the conversations about LR. I think the next version/update will be significant.
Later!
Guy's point about the effects of Relative vs. Perceptual help illustrate why the effects of profile conversion vary from image to image and depend entirely on how the destination profile relates to the actual color values in the file.
Regardless, you'd be hard-pressed to find a ProPhoto file that came from a 16-bit (actually 12 or 14-bit) digital camera capture and processed into 16-bit ProPhoto that would fit entirely into the sRGB space. (Interestingly, sRGB actually has a wider gamut in the greens than even ProPhoto, though reds will suffer.) That's why there will always be some colors that get remapped to new values in the destination space; it's just a question of if you can see the difference or not.
So I almost always try both Relative and Perceptual, and use the rendering intent that looks the closest to the original.
Anyone seriously interested in the nuts and bolts of digital color should read Real World Color Management by Bruce Frasier et al. It's a heady read but really thoroughly explains how this all works.
An interesting side note - one of the coolest features of Lightroom is the modular architecture. It's expected that a lot of the new functionality (like Photoshop plug-ins) will be implemented as standalone, third-party modules that will be accessed from the module picker and/or the panels. To me, this holds a lot of promise: applications within an application that essentially could do any kind of image processing the software developer envisions.
I agree, Bruce's book is great. I actually enjoy color management and color theory. It's easy to get deep quick, though.
I'm watching, with interest, for the the Lightroom SDK. Depending on price and capabilities, I've got some development ideas for my spare
Hey, do you know of any good CS3 upgrade codes or offers to discount the $199? I haven't upgraded yet but plan to.
Thanks again!
If you are a student or a teacher with some kind of insitutional ID, or know someone who is, and don't have an eligible version to upgrade from, this is the cheapest way to the full version of PS CS3. Some Google searches for academic software discounts will turn up the major players.
I think for most serious photographers Extended will be worth the extra $$$.