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The sRGB Conundrum
Exporting images out of Lightroom is one of the simplest tasks imaginable. But what you may not realize or have thought about is what happens when you export images in a color space other than ProPhoto RGB. I bring this up because Lightroom by default uses a ProPhoto RGB color space with an sRGB tone curve. What this means in layman's terms is that while working up your images you are essentially working in a ProPhoto RGB color space which is huge compared to an sRGB color space. And there are subtle changes in your images if you export them in any color space other than ProPhoto RGB.
Don't ring the alarm bells just yet - this isn't a critique of Lightroom - this is just how it is. Let's say that you work up your image in Lightroom setting the white and black points using the option key as I wrote about in last weeks blog post. This allows you to set with great precision the white and black points of an image - in the ProPhoto RGB color space. When you export that image as sRGB and then open it in Photoshop you'll notice that your histogram is a little different than it was in Lightroom. You might even see some clipping in the shadows and highlights. This isn't rocket science. You just converted your precisely worked up ProPhoto RGB image to a smaller color space and because of that the histogram is going to change.
In some cases the change is so small that it is irrelevant. In other cases it isn't. Here is an example of one image that was exported as an sRGB file to be used online. You'll notice in the first histogram (from Lightroom) that there is ample room on either side of the histogram and all looks good. In the second histogram (from Photoshop's Levels dialog) of the same image in the sRGB color space we see that both sides are clipped. And in this case the difference is drastic. Though if you could see the sRGB image it doesn't look appreciably different on my monitor than the ProPhoto RGB version - mostly because my Apple Cinema Display only renders the sRGB color gamut. The image still looked just fine but I wouldn't want to send an image with this histogram to a client to publish in a magazine.
So the moral of this story is know what color space you are working in and where your images are going. This is also the main reason that I always export images out of Lightroom in a ProPhoto RGB color space and then in Photoshop I can convert the images to Adobe RGB or sRGB as needed but with a lot more control.
As an aside - if you want to work up your images in an sRGB color space with more control, Adobe Camera Raw (ACR) changes the histogram depending on which output color space you have chosen - because you can set this in ACR before you open the file into Photoshop.
As I said before this isn't a reason to abandon Lightroom - just one of those things to be aware of if you are exporting your images out of Lightroom into an sRGB color space. For many folks, you might not even notice any change in the images at all. Another workaround is to just leave a bit of room on either side of the histogram as you work those images up in Lightroom, then export the images and wait to make final histogram settings in the Levels dialog in Photoshop.
That's it for this session. See you next week.
Adios, Michael Clark
Interesting article Mike.
I heard some of the developer podcasts with George Jardine. In one of them I believe that Mark Hamburg said that even though the photo is internally manipulated in ProPhoto RGB the LR histogram is based on an sRGB colorspace.
But your sample and article would say that the histogram in LR is not sRGB, right?
Mariano -
The histograms don't lie - they are quite different, especially in this example. Mr. Hamburg obviously knows much more than I ever will but from my experience this is what I have found....
Just stumbled on this blog, while searching for a solution for this exact problem. Situation: I often have to deal with large groups of photos (1000+), which can't be given to the client in any color space other than sRGB. Working with lightroom, I can be pretty sure that: 1) the client will get crappy images; or 2) I will have to work all the images in lightroom, than check on all of them (making adjustments as I do) on photoshop, while converting to sRGB.
My conclusion is that this is more than enough reason to dump Lightroom. It simply beats me why such a great program has such a HUGE flaw.
Is there ANY type of workaround for this? Is there ANY possible way to export into sRGB (the industry standard) and NOT lose color information?
Saving in Photoshop has the same problems. As soon as the document leaves LR or PS the color profile seems to be thrown out the window.
What is the fix to this? Telling us "be aware" is useless. We are glaringly aware that the images we work on look poor when we export them. How do we fix that?
The workaround is to export images in the ProPhoto RGB color space and then convert the images to sRGB in Photoshop. And basically leave some room on either side of the histogram when processing images in Lightroom that you know are going into the sRGB color space.
No color profiles are being thrown out. It is just the fact that we are working in a ProPhoto RGB color space and adjusting images according to that color space in Lightroom.
If you want to avoid all of this confusion you can simply use Adobe Photoshop's Camera Raw where you can set your color output settings before you work on the images. That solves the problem. Perhaps the Lightroom engineers will change their approach for Lightroom and rectify this issue by allowing up to set the working color space in the next version of Lightroom.
Mike -
Another thought. I'd say sRGB is not the industry standard. If anything Adobe RGB (a larger color space) has become the industry standard and will become more so as monitors become better and are more able to show that entire color space.
sRGB is the default color space for many amateur photographers because it simplifies the color management process to some degree. That is why all cameras come with sRGB as the default color space - it isn't the best color space - it just allows folks with uncalibrated monitors and printers to get half-way decent prints without as much work as it would if they tried to shoot in Adobe RGB.
So the problem I have with ProPhoto RGB is that the images -still- look distorted compared to the pre-export version. I am working on a calibrated monitor so I am quite certain monitor is not the issue here.
The following link is a screenshot that illustrates exactly what I'm talking about. The LR2 version is the large image on the left. ProPhoto RGB is top right, and sRGB is bottom left. The LR2 version looks almost like a mix between the sRGB and ProPhoto RGB.
http://imgur.com/0u1Bj.jpg
Should I just switch all my color profiles to ProPhoto RGB (camera, lightroom, and photoshop) and work from there?
I am also interested in using this camera raw idea and would be interested in more information. Specifically, is there a way to hop from lightroom to photoshop via camera raw?
Allow me to explain: I color correct photos in LR then pull them directly from LR into photoshop. It's only once I'm ready to save for web that my images look different. Sometimes this difference is drastic - again it depends on the photo. How do I use Camera Raw as an intermediary between LR and PS so that what I edit in Photoshop will yield the same image I see after export?
You can switch all of your profiles to ProPhoto RGB or you can just use ACR (Adobe Camera Raw) instead of Lightroom. There is no way to go straight from LR to ACR.
Occasionally, when exporting from LIghtroom I get a color saturation loss, regardless of the file format or color space I am exporting to (always from a Raw file). This happens whether I do file/export or edit in another app. and then back to Lightroom as a Tiff. In PS it doesn't matter what I choose as the working color space, including Prophoto. Same problem. Only seems to happen with photos that have green foliage but then it not only effects the green but most other colors as well. Does this relate to what you are discussing above?
Current versions of Lightroom and and PS.
Monitors calibrated with Xrite Eye1 Display2.
David -
I used to see this every once in a while and sometimes I think I see some desaturation in PS compared to the LR version but then when I compare them with both programs open I can't see any difference at all. It might have to do with the darker interface in Lightroom versus the lighter one in PS. Not sure.
I just looked at several images in PS and LR and compared them - in a variety of color spaces - and I couldn't see any color differences. If they were there they were so subtle that I couldn't really tell. I have LR V2.4, PS CS4 and and Apple display - all calibrated with the i1.
I for one would like to see Adobe drop the fixed color space in Lightroom and will mention this to them. I'd prefer that they have the classic color space (as it is now) but also allow us to specify the color space we want to work in like Photoshop so we can avoid all these issues.
It has been suggested to me that the problem I have described is due to Melissa, i.e. the Lightroom color space, which is a variation of ProPhoto. If this is the reason, then I think Adobe screwed up an excellent product. Having more linear adjustments is worthless to me if it screws up the colors in some of my photos. What I am seeing goes far beyond what happens when you go from ProPhoto to sRGB. At least you still have a good looking picture with this conversion, if not quite as nice as before. What I am describing makes the picture look bad.