Anaglyphs
How they work and how to make a viewer

Anaglyphs (from the Greek anáglyphos: "wrought in low relief") combine the two images (as shown on our stereo images pages) into one image, with the different channels (left and right) displayed in different colours. We choose to use red and blue (somewhat a de facto standard nowadays.)
Stereo pair of badge At left we have a stereo pair of the PHS school badge. For this example, the right-hand image is (almost) the standard badge, whilst the left-hand image has been manipulated to simulate the stereo image.
2 colour pair Here the two images have been coloured. The blue image is the one which the left eye (only) should see. The red image is the one that the right eye (only) should see.
If you view this through the coloured glasses, and close your left and right eyes alternately, you will see how this effect is achieved.
merging... Here the two images are partially merged, to demonstrate how the overlapping sections become black.
analglyph of badge

Here the two images are aligned.
This is the final anaglyph, which can be viewed in stereo through the glasses.

red/blue glasses How to make the viewer red/blue glasses

Fortunately this is quite simple.
You will need some cellophane®, or transparent coloured plastic sheeting. The colours (red and blue) should be quite dark - or saturated - as pale tints will yield double images when viewing.
Simply cut out a cardboard "mask", similar to the ones shown above, to suit your eye spacing. Cover the left eye space with the red plastic and the right eye space with the blue plastic. Don't forget a nose cut-out.

Of course, you can just hold two scraps of cellophane® in front of your eyes, but its much neater to make a viewer!

If, at any stage while you are viewing anaglyphs, you find the stereo effect is badly distorted, or somehow just "wrong", then you probably have the glasses on backwards.
Remember... red is left - blue is right.


Links to both the stereo pairs and the anaglyphs on are the same menu pages:

Proceed to the first page of stereo images.
Read the stereo pair help page.


Click to return to home page
These and the following images are © PHS