Learning to view in stereo

There are different ways of producing a stereo effect, including single images that are viewed through red / green glasses. However, this method – two matching photos that make a stereo pair – produces the best stereo images.

Without a viewer such as the Pokescope, viewing can be awkward but it is still possible. One way is described here, in the right-hand column.

Why view in stereo?

While it is fun to see flat photos suddenly pop up in 3D, stereo photography has a serious side, too. The examples shown here (see links at left) demonstrate uses in biology, space exploration and geology.

Make your own stereo viewer

All you need is the cardboard middle from two rolls of paper towels – these are about a foot / 30cm long. With a stereo pair on-screen (such as one of the stereo examples), use the two cardboard tubes as if they were a pair of binoculars. You should be able to see just one image through each tube.

With both eyes open, move your head backwards and forwards until the two images click into one. And there you have your stereo viewer. Not elegant but, I hope, effective.

If you keep the tubes level, vary your distance to the screen and allow your eyes to relax, then you should have no problem with viewing stereo pairs on your computer screen. (If you have no cardboard tubes, rolled-up paper will work just as well.)

Cross-eyed viewing

Some Internet sites (including NASA’s) may swap the left and right stereo views and invite you to view the image cross-eyed. Some people find this easy and convenient. For others, it gives them a headache. However, the stereo pairs on this site are intended for wall-eyed (straight-on) viewing.