I need to make one for my school but I haven't found how to do one !
The freeware program ImageJ can help you. Here is the stereograph plugin .
Take two disposable cameras. Mark one R and the the other L. With camera R, take a picture of a sheet of paper with a big R drawn on it. Do the same with camera L, using paper with a big L on it. Tape the two cameras together so that you can see through both viewfinders at the same time, R on your right eye, and L on your left eye. Make sure not to tape over anything you'll need, like the film advance wheel, the flash charger or the lens. Take a bunch of pictures with both cameras simultaneously. Extra points if you can get the Eiffel Tower or the Leaning Tower of Pisa. When you've used all the shots, untape the cameras and send them in for processing. Be sure to tell the processor that you want all the prints, not just the ones that the processor thinks are the "good" ones. While waiting for your prints, make a stereoscope out of a ruler, a couple of binder clips and an old pair of welding goggles. When you receive your prints, the first print in each envelope should be either the R or the L papers. This tells you which set of prints is from which camera. Tape the matching prints together on the appropriate sides, put into your stereoscope and enjoy the vertigo.
Take two pictures, from locations three inches apart horizontally, centered on the same location on the horizon. Put the prints next to each other, and llok at one with one eye and the other with the other eye. See also the items in the "related" column at the right.