David Cardinal: A Photographers’ Survival Guide to Color Spaces
Sep 2012 20

Have you ever put a lot of work into getting an image just right and then sent it off to a friend or an editor and had them say it looked washed out? Or have you taken a perfectly good-looking image and sent it off to a service bureau only to get back a print that looked like mud? Or maybe you thought you’d tweaked out the ultimate in detail from a subtle sky and had your prints look posterized?

If you’ve had any of these problems, or just wish you knew how to set up color spaces in your workflow, this article provides a survival guide to help. Color spaces show up in camera menus, image editing software, and print drivers. Understanding how to make use of them is key to successful image editing and reproduction. Like most things in photography once you know about it you can find endless and often contradictory advice about what it is and how to deal with it. We’ll give you a grounding in what they are, how they’re used, and some tips on how to get the most of them, depending on your workflow.

What’s a color space?

I’ll start with a simple definition of a color space. It is a map of the numeric values of the pixels in your image to “real world” colors. There are “small” color spaces like sRGB, which map your pixels into the least common denominator of color display found in inexpensive TVs and web browsers, “medium” color spaces like Adobe RGB which approximate the color fidelity you might find on a higher-end monitor or D-SLR and “large” color spaces like ProPhoto RGB (developed by Kodak) which can contain colors far beyond what we can currently capture or even see.

Why color spaces are important

Unfortunately if you care what your images look like you need to care about color spaces. Specifically if your image is encoded in one color space and displayed in a different one, then it won’t look right. For example images encoded in Adobe RGB look washed out when displayed on an sRGB device.

But if all this is making your head spin you can “opt out” of this whole issue by simply choosing sRGB as your camera color space and your Photoshop color space and leave it at that. Then all your images will look okay on just about every device, as it is the smallest and therefore the “safest” default. Since it’s such an easy solution, you might ask why we don’t all do it.

These pumpkins were out of gamut in sRGB, but fit perfectly in Adobe RGB

Simply because our world contains many colors that don’t fit in sRGB, and most DSLRs, high-end monitors and high-end printers can now work with those colors. So if you want the richest and most accurate images you need to deal with at least a little color space complexity.

sRGB Gamut vs. Adobe RGB Gamut

What about just using a huge color space for everything?

Yes, you certainly can. That’s what ProPhoto RGB is and if you browse fine art photography sites you’ll find plenty of folks who recommend you stick with it as the space you set in Photoshop (in Edit->Color Settings you can change the RGB color space Photoshop uses by default, called its “working space”). There is just one large issue with this approach. Because ProPhoto RGB is a huge space it requires a huge map to cover the territory.

That means if you are going to be working in it you really should be using a 16-bit workflow—opening your images in 16-bits (Lightroom does this, which it calls High-bit, internally) and saving them as 16-bit image files (really 48-bits per pixel, as each color gets 16-bits). That doubles the disk space your images need and slows down their processing dramatically. On top of that not all Photoshop plug-ins operate on 16-bit images (yet).

If you’d like to learn more about 8-bit versus 16-bit workflow you can see the article we published in DPS 4-13 in 2007. Fortunately there is a way to tell when you need a truly large color space, which I’ll get to later in this article. In the meantime the good news is that there is a really good choice for a general purpose working space.

Hot-air Balloon in ProPhoto RGB vs. sRGB – Even though they were both later converted to sRGB for the web you can see the additional richness of the ProPhoto RGB version on the left.

Adobe RGB: The Goldilocks Colorspace

Adobe RGB turns out to be a really good all-around color space. Most modern DSLRs let you choose it as the color space they output when you capture JPEG files and many newer monitors even let you set them to try to match it. It is a convenient default for Photoshop as well. Adobe RGB is just about big enough to hold all the colors you’ll capture most of the time, but small enough that you can typically get away with an 8-bit workflow—saving you processing time and disk space.

To use Adobe RGB you need to do three simple things:

  1. Set your camera to record images in Adobe RGB if you shoot JPEGs.
  2. Set your Photoshop Working Space to Adobe RGB (Lightroom uses Pro Photo RGB as its working space, but allows you to choose a different one when you export images)
  3. Remember when you send an image to anyone not using a fully color managed system (when it doubt assume they aren’t) to convert the image to sRGB. Many programs make this easy with a simple checkbox when you use commands to “convert” or “Publish to web” on your images.

The screen shot on the left shows an out of gamut image in Adobe’s Camera Raw using sRGB. The screen shot on the right shows the same image in gamut with ProPhoto RGB.

That’s all there is to it. If you forget step #3 your images will look washed out on other peoples’ computers or when you send them off to a consumer online print service. That’s the price you pay for the extra rich colors of Adobe RGB. The only other trick is deciding when Adobe RGB isn’t big enough

When Adobe RGB Isn’t Enough: Move over Goldilocks

Using Adobe RGB is as we’ve said, a compromise. For some images your camera will be capturing colors that are simply outside its range. If you have a high-end printer it can even print many of those additional colors. However, once you’ve put an image through the bottleneck of Adobe RGB in the middle of your workflow, you can’t get those additional colors back. The trick is knowing when you have those extreme colors in an image so you can kick it up a notch and use ProPhoto RGB & 16-bit processing end-to-end.

There are many tools which help you look at the colors in an image but the good news is you’re probably already using the handiest. When you first set your Raw file options Adobe provides you with a handy histogram of the image. You are probably already using it to determine whether you have blown out highlights and need to use the Recovery slider, but it is good for a lot more than that. Since the histogram is RGB, it can show you whether a particular channel is saturated.

If looking at your image you see that your problem isn’t blown out whites but over-saturated colors that’s your tip to do a quick shift to ProPhoto RGB (Lightroom starts with ProPhoto RGB). The image below, for example, is of the inside of a hot air balloon and Adobe RGB just couldn’t contain the vivid red hues:

This hot-air balloon image was out of gamut in sRGB and Adobe RGB but rendered correctly in ProPhoto RGB.
Nikon D700, Sigma 24-70mm f/2.8 Lens

TIP: Switching to ProPhoto and 16-bit in Photoshop’s raw processor is easy. Simply click the “Options” link at the bottom of the Camera Raw screen and change the settings in the resulting dialog to ProPhoto RGB and 16-bit (don’t forget to change them back on your next image).

If you’re right that the problem is over-saturated colors then you’ll see your histogram snap back into line without any nasty highlight and lowlight warnings. If it doesn’t then your problem may not be related to colors.

Once you’ve done that simply process your image as usual. The only caveat is that since your image has some really radical colors it may be hard to print in full fidelity. You’ll need to make extra sure to soft-proof through your printer profile to see how it renders the extreme hues and possibly do some tweaking in your image editor to make them come out the way you want on the printer. And you need to make extra sure that you convert the image to a smaller color space before sending it to anyone or it will look awful on their display.

Matching color spaces to your digital workflow

Datacolor’s David Tobie has a great way to describe how your choice of color space and bit-depth interact with the needs of your workflow. He describes a funnel – pictured here – where your raw camera data is at the top. Your raw data represents the most information you can get from an image. It isn’t recorded in any of the standard color spaces we’ve discussed, but it is in a de facto color space described by the spectral sensitivity of your camera’s sensor.

Once you begin to process the raw data, you get to decide how far to go. For maximum fidelity (at a cost in disk space and processor time) you can leave your images Raw and process them in Lightroom or Nikon Capture, or as Smart Objects in Photoshop. If you need to hand them off to other applications, or to use the advanced features of Photoshop, you can turn them into 16-bit images in ProPhoto RGB and save them as TIFF or PSD images to lose the minimum amount of your raw image information.

For more typical uses, and smaller images to work with, an 8-bit version based on Adobe RGB is usually just fine. Remember though, that Adobe RGB images are still only good for handing off to those who also color manage their system. If you don’t know where your image is going, or it needs to look good on the web, converting to an 8-bit RGB JPEG encoded with the sRGB colorspace is the safest, and smallest, way to go.

That’s all there is to it. If you’d like to learn more I highly recommend Color Confidence: A Real World Guide To Color Management by Tim Grey (look for my photo of a Moose on the cover). Real World Color Management is also excellent but hasn’t been updated since Bruce tragically passed away.

Let us know any tips or tricks you have for making the most of your color management workflow.

is a veteran travel and nature photographer who specializes in Southern Africa and Southeast Asia as well as North American mammals and birds. His images of creatures in the wild help communicate the importance of our natural heritage and our responsibility to preserve it. You can learn more about David on our Friends with Vision page, or on his own website, Cardinal Photo, and its sister site, Nikon Digital, which are both full of tips, reviews and forums where photographers compare notes and tips. Or you can follow David on Facebook or join him on one of his Photo Tours and Safaris for plenty of experience