There are many ways to produce a stereo image, some more high tech than others: stereo cameras, two cameras, digital manipulation of a photo or drawing.  One of the simplest is just to place two identical objects a few inches apart, and photograph them.  You then get two perspectives of the same image, and you can watch it pop into relief in your stereoscope.

For quick, low tech experimentation, you can easily make simple stereo pictures with rubber stamps.  You’ll need stamps, index cards, and a lightbox.  If you don’t have a lightbox, sit over a desk lamp with a picture frame on your lap.

Choose two stamps, one for a close image, one for a distant.  Rule an index card in half.  On the left side, stamp the stamps in the position you want for your picture.  This will be your reference picture.

Rule another card in half, and place it over your reference picture on the lightbox.  On the left side, stamp each stamp in the same position as on the reference.  Neatness counts.  Then, place the right side over the reference, stamp the close image slightly more to the left, and the far one slightly more to the right.

Of course, this isn’t fully dimensional: what you’ll get is two flat images on two planes (cardboarding, we call it).  But it’s fast, it works, the irregular inking causes a shimmering effect that is pleasing to the eye, and you’ll probably get ink on your hands.

And you can move on to three planes.  For this, follow the same recipe, but add a third image to occupy the middle ground.  On the right side, stamp that one in the same position as on the reference: close image to the left, middle one stationary, far one to the right.

The crucial part is in the positioning: too little separation produces no effect, too much will be rejected by your picky brain.  You’ll see.

I find these pictures easy to view with free vision, even though I’m not too good at that.  Maybe it’s because they’re small and simple.  Focus on the opposite wall; hold your picture up against your nose.  Move it away slowly, until your brain cooperates and gives you a blurry stereo image.  Keep moving it to focus it.

If you want to use the crossed-eye method, you’ll have to cross the images: that is, on the right side, the close image must be more to the right, and the far one more to the left.  Then, stare at the damn thing, cross your eyes until the images join, and stare at it some more.

Experiment, and have fun with your eyes and brain.

(Posted by Doug Skinner)