A study of colour - Part 2: colour gamuts (spaces)

The colours here may not represent the actual colours from the scene.  Screens and prints do not have the same broad ability to display all the colours of the spectrum.  The range is the colour gamut.

What is a colour gamut (also called a colour space)?  Essentially, it is the entire set of colours that can be displayed on media.  Although there are millions, even trillions of colours available in a file or print, they do not represent every single colour originally present.  Even our eyes are limited in that there are colours they cannot pick up that exist in nature.  The colours that we can see are the visual colour gamut.  The ones that can be seen in print or electronic media are other colour gamuts.

How many gamuts are there?  In Photoshop, there is an almost unlimited number.  To see the list in Photoshop, Click on the top menu View > Proof Setup >  Device to Simulate > and then look at the list - there are hundreds of choices.  And you can download even more.  Each media type, camera type, scanner, and so on, has its own gamut. The range of colours that a device can capture, print, or display is quite varied.  The image below (click here to see the original) shows the total variety of colours visible to the human eye and 4 different colour gamuts.

Your digital camera may be able to choose a colour gamut.  Typical gamuts are Adobe RGB and sRGB.  The most commonly used one is sRGB, which you can see above (blue triangle), and Adobe RGB (red triangle).  You will notice that Adobe RGB has a wider colour range than sRGB, which is why it is often used by professionals.  The sRGB gamut is best for digital viewing as most monitors can accommodate its range of colours while Adobe RGB's colour range is better suited for printing.

We will look at colour printer colour gamuts in my next blog.

Thanks for reading.

Eric Svendsen     www.ericspix.com