Subtractive Colours

I was curious to see how my colours photos would turn out using a different colour scheme. Usually I use red, green, and blue filters to capture an image – much in the same way that a digital camera uses a series of red, green, and blue filters over its sensor to capture a colour image.

Red, green, and blue are additive colours. By adding those three colours in different amounts we can create a range of colours. It is also how your retina works, with cells sensitive to red, green, and blue light. This is why devices that emit light use an RBG system.

The other type of colours are subtractive and those are cyan, magenta, and yellow. They are used in print to create the colours for our eyes. These subtractive colours absorbe their opposite additive colour and reflect back the other two additive colours.

Say, cyan absorbs red and reflects green and blue (which make cyan of course). By placing pairs of subtractive colours, you can create one of the additive colours. For example, cyan and magenta would absorb red and green respectively and reflect blue. Check out the diagram on x-rite to get an idea.

It seems counter intuitive to do this, but print material does not emit light, it reflects it, so we must reflect the right combination of RGB to your eyes.

Now onto the phots that I took using cyan, magenta, and yellow filters. The effect of forcing subtractive colours onto an additive photo system turned out quite nicely and also eerie. Enjoy.