What is gamut?
Every color system whether on monitor, desktop printer, digital press, copier, offset press, etc. has its own unique color gamut.
Color gamut is a range of colors and tones. The color gamut of a computer screen is determined by the purity and brightness of its red, green and blue pixels. The color gamut of a printing device is determined by the hue, saturation and lightness of its cyan, magenta, yellow and black inks, and by the brightness and other characteristics of the paper or substrate on which they are printed.
Successful designers work within the available color gamut—or accept some loss of color in the final output. For example, if you view your design in RGB without CMYK soft proofing, chances are you will be disappointed when it prints. Likewise, don’t expect the same color gamut on newsprint as you can get on commercial offset paper.
The gamut of a photograph
Apart from what a display or camera can show, a photograph also has limitations. A printed photograph or a polaroid, for example, will show different colors due to the nature of its materials and chemicals.
A digital photograph is not constrained by material, but by mathematical and “genetic” ones. The genetic ones are deficiencies passed on to it from camera sensors, processing, and circuitry.
E.g., if you shoot a photograph in Adobe RGB (a larger color space), you are bound to collect some colors that are outside the scope of sRGB. The camera sensor is able to do this because it has a gamut greater than sRGB. This photograph is said to be in a different color space (defined by Adobe RGB), but it also has a gamut (the actual colors within this space that the sensor and camera electronics were able to put into the digital file).
If this photograph is viewed on a monitor displaying sRGB, then the colors will look off. That’s because the mathematical basis of one color space is different from another. For simplicity’s sake, even though this doesn’t happen in practice, let’s say if we are able to normalize these two, you’ll see your photograph, but with some colors missing. These missing colors are the colors that are defined under Adobe RGB but are beyond sRGB.
The story doesn’t end here. The above is only possible if the monitor itself shows sRGB in its entirety. If it’s a cheap consumer-grade monitor that can only show 90% of sRGB, then you’ll find more colors missing from your photograph. They’re still there in the file, but your monitor is unable to show them.
The following is a list of display technologies in descending order of gamut ability:
- Laser projector
- DLP Projector
- LED/LCD/CRT Monitors
- Consumer television