The Difference Between Reflected Light and Projected Light

Reflected light is composed of a certain percentage of each true primary colour (Yellow, Red and Dark Blue). If we consider a mid Green consisting of 50% Blue and 50% Yellow, the reflected energy is much less than the same area having all Yellow. It is also much more than the same area having all Blue.

If you think of any pigment as a number of very small tiles each having its own colour, then if you only have Yellow tiles and Blue tiles to play with, your overall possible perceived colours are limited to all Yellow, all Blue or limited shades of Green. The maximum energy emitted from any area of the pigment would be if only Yellow tiles were used.

If you have some White tiles you can have a lighter Yellow, a lighter Blue or an extended range of Greens i.e some lighter.

If you have some Black tiles you can have a darker Yellow, a darker Blue or an extended range of Greens i.e some darker.

With projected light it is more more complex. There are two different situations with projected light.

Type 1. If you have source of ‘true’ Yellow light that shines through a series of small square holes separated by similar sized  small Blue filters., the resulting colour will be a light Green. This is because some of the Yellow light will pass through the Blue filter producing a dark Green. This dark Green, when added to the Yellow will create the light Green. In comparison with the coloured tiles in which we had Yellow and Blue tiles, we now have, in effect, Yellow and dark Green tiles. {See Colour Filters}

Type 2. See Projected Light.

Author – Brian Williams.