Most photographers are aware of the difference between using Adobe RGB and sRGB when shooting photos. Adobe RGB has a bigger color range than sRGB. There is a misconception though regarding Adobe RGB and sRGB when I give lectures about basic color management.
One of the questions that I ask participants is if Adobe RGB and sRGB are examples of a color space, a color gamut or a color profile?
The most frequent answer is that they are color profiles.
Let’s clarify a few things by defining color space, color gamut and color profile.
A color space is a range of colors as defined by its primary colors (ex. RGB, CMYK) and it is device independent.
A color gamut is a range of colors as defined by its primary colors and it is device dependent.
How does this apply in digital photography?
All digital cameras can shoot using sRGB. Why? Because sRGB (like Adobe RGB) is a color space. It isn’t linked to a specific device. This makes it device independent.
I use two different cameras as my workhorses – a Canon EOS 7d Mk1 and a Canon EOS 5D Mk3. Let’s say that I set up both cameras to shoot the same scene at the same time with the same ISO and exposure settings and with the color space settings of both cameras set to sRGB. The digital image produced by each camera would have colors that don’t exactly match each other.
Color gamut is the unique way that each camera or device produces colors in a color space.
What’s a color profile? A color profile is a range of colors that is defined by its primary colors and it is device dependent. The color profile also contains a look up table which will always refer to a reference color space.
Think of the reference color space as a universal dictionary of colors that allows the color profiles of different devices (ex. camera, monitor, printer) to communicate with each other.
Color profiles that allows us to almost faithfully reproduce colors across different devices.
That’s one of the reasons why I encourage my students to embed the color profile whenever they save their post processed files.
Embedding the color profile allows color savvy computer programs (programs that recognizes color profiles) to better handle and interpret the colors of your digital image.
In a nutshell, Adobe RGB and sRGB are color spaces because they are device independent. Color gamut is the unique way that a device creates color within the color space. The color profile describes the color gamut of a device in a given color space, which it can then communicate to other devices that also use color profiles.
(I would like to thank Idealliance for having taught me the simplest definitions that I have ever come across for color space, color gamut and color profile.)