RGB: The Universal Color Space

RGB is really the only legitimate color space. We see in RGB. Cameras record in RGB. All other color spaces come out of it - LAB, CMYK, etc. But as photographers, all we care about initially is RGB - and which one to shoot in and process in.

RGB comes in several flavors too. On your DSLR, you can choose between sRGB and Adobe RGB for JPG shooting - RAW is a different story. For RAW there's another color space just waiting to be discovered. Here's the short list:

sRGB is the smallest color space and designed for use on the web, for thrifty prints at White House Custom Color, JPG's sent your Mom and clients, slide shows and web galleries - in other words, monitor viewing and small photo prints. sRGB's narrower color space compresses wider color gamuts to print/view most acceptably on low end devices - again, monitors and small prints. Opening files in this color space will always result in clipping of some colors - don't shoot in sRGB unless you don't have anything else - view it as an output space.

Adobe RGB is a wider color space that translates well into high end print media. While bigger than sRGB - and the preferred color space to shoot high quality JPG's - there is still clipping of some portions of color . It's most useful as an output color space for commercial printing and custom enlargements after conversion from RAW postprocessing in the ProPhoto color spaces. Therefore, Adobe RGB is also not the best starting point for original image files. What! Why? Because it does not contain all the colors your sensor can capture - read on...

ProPhoto RGB is the largest color space RAW images can be converted to after they are captured off the camera sensor. Read that again. ProPhoto RGB is actually a wider gamut than the human eye can see, which is perfect for our purposes. Postprocessing and editing RAW files in ProPhoto RGB can be performed in an 8-bit or 16-bit color depth and will retain all the sensor's pixel information until you convert to either a Adobe RGB or sRGB color space for monitor viewing and prints.

Unlike Photoshop, Lightroom does not burden much color management on us and has removed most if not all the color space concerns for us - it uses ProPhoto RGB as a RAW conversion default and allows us to convert to Adobe RGB and sRGB at the time of output. I like that - even if I can't see it on my display. Keep your monitor well tuned - or buy a decent one to start with - and you will spend more time working on your images and less time worrying about color spaces.

Mule