Chapter IV

Playing on the green

Magenta and white stereo is not interesting, black and white should be better, but color should be much more interesting.
So, how can we produce color stereo images on the screen?
Flat color images are made with three bands.
This means that the three bands will probably also have to be used for color stereo.
From which image must we take the green band ?
Red and green filters are opposite and turn to dark if added.
In contrast, blue and green filters are not opposite and turn to cyan if added.
The green information must come from the same filter as the blue.
This means that the blue and green band will both have to come from the same image: the right one.

Why use the red filter on the left and the cyan on the right ?
It could be the reverse but the International Stereoscopic Union has chosen the red on left for standard disposal.
It is also in coordination with the red used in international marking such as: ships, planes, and politicians !

Now, if you convert a stereo pair into a color anaglyph by separating the bands and after, glue them, you will be able to see in stereo and in color directly on your monitor by just using red-cyan anaglyph glasses.
Easy !

If you do not have anaglyph glasses with a cyan filter, you can use ones with a blue or a green filter: stereo 3D effect will remain but colors will change.
With a blue filter, colors will slightly shift to blue.
Avoid green anaglyph glasses as it wipes really too much colors.