Notes to myself: About colour space

The Wikipedia has a somewhat comprehensible explanation of colour space. This is not an easy topic, but eventually one needs to come to grips with it in order to work with colour, whether as an artist, a photographer, a graphics designer, etc.

I have often wondered about RGB, sRGB, and CMYK. Now I know that sRGB is the "standard" RGB that I ought to use in photography. CMYK is used for printing. It is not necessary to go into the theoretical explanation of all these.

I have also learned that oil painters work with the HSV components of colour, while digital photographers use its close cousin HSL. HSV stands for hue(or chroma)/saturation/value(brightness), while HSL stands for hue/saturation/luminance(lightness). Wikipedia explains that the difference as "the brightness of a pure color is equal to the brightness of white, while the lightness of a pure color is equal to the lightness of a medium gray."

For a photographer, to understand HSL, it is best to play with the HSL sliders in Lightroom.

- First, click on Hue under HSL. Each colour slider will effectively change the corresponding colour in your image. For example, blue can vary from turquoise to purple. (Hue is otherwise known as colour in plain English)

- Next, click on Saturation under HSL. Each colour slider will effectively unsaturate (become black-and-white) or saturate the corresponding colour in your image.

- Finally, click on Luminance under HSL. Each colour slider will effectively make the corresponding colour in your image darker or lighter.

There you go... there is no more mystery about sRGB or HSL!
Follow the Nike slogan: Just Do It!