For a brief overview on how/why stereophotography works,
Click Here.

I use a Revere Stereo Camera 33, made in the 1950's.
(Wollensak 35mm f/3.5 Amaton lenses.) I took it with me when I went travelling around the U.K. and Scandinavia, in 2003 - and took rather a lot of photos!

I still use it from time to time even now,
for the occasional special event, or roadtrip.

It uses standard 35mm slide film.

The drawback to a square format of film, is the difficulty in scanning it.
Whilst it is absolutley possible, it does take an annoying amount of time!Attempts in by-passing the scanner, by photographing the slides directly against a bright light source, here:

Random Assortment from 2003 (Orkney, Iona, Arran, Oslo)
Red Hot Chilli Pipers 2011
(Juice Bar, Auckland NZ.)

Current setup needs work - too much reflectivity and other interference, but still enough to get the idea!
(flickerpics made, using Stereo Photo Maker

Stereo-pairs (click to enlarge)

Graham   Gundestrup Cauldron   Peter Jackson

Sit comfortably back from your screen, and allow your eyes to relax. If you need help, try holding your finger in front of your nose, and focus on your finger as you move it slowly towards the screen. If things are working right, at some point you should notice an illusion of three blurry pictures where there is really only two. Gradually allow your eyes to drift onto the "middle" image from the tip of your finger, and let it come into focus. It should look (hopefully) 3-d ish!

Flickerpics - no effort required. Just click, to load the animated gif.

A lovely Vendel Helmet!...