There are two main ways of viewing 3D stereoscopic images on a screen with no special hardware at all. These methods can be used with specially prepared photos, movies and websites.
One type of 3D image which you can view on a 2D screen is called an anaglyph. You know, the type that’s viewed using those cardboard glasses with red and green lenses. You might consider this method old hat but it’s so simple and a lot more effective than you might remember. The first anaglyphs were monochrome but colour was added later. We’d be lying if we said that colour accuracy isn’t sacrificed, the end result can be pretty impressive.
An anaglyph comprises the left and right images superimposed on top of each other, one printed in shades or red and the other in shades of cyan. Because the red lens in the glasses passes the red image but stops the cyan image (it’s not green, it’s cyan) and vice versa. Each eye sees only the correct image. And because, between them, the two lenses allow all the three primary colours of red, green and blue to pass, a full colour image is achievable.
In terms of content, some DVD movies are available as anaglyph 3D versions and there is no shortage of galleries of anaglyph photos and movie clips online (try a YouTube search to see what we mean). Even Google Maps has anaglyph support – just press the T key while in StreetView mode (you must click on the image first). Glasses for anaglyph viewing are widely available for pennies if you buy them in bulk, otherwise you’ll pay a pound or so for a single pair.