Stereo Pairs are created by taking two images offset slightly from each other. Offset like your eyes are offset, left and right.
A stereo camera can take these to images at the same time. Stereo cameras are basically two cameras built together side by side.
My “stereo” camera is my single Canon 7D. I can not take two images simultaneously. I have to take one image, then shift the camera to the left or right then take another image.
This first image was take from the window of an airplane at 500 or so MPH. The distance between the two shots is great. The subject being so far away makes this OK. To view these images click them to make them larger, then, with your head level with the monitor, slowly cross your eyes until you see three images, the center one is the 3D combination of the left and right images.
To offset my two images left and right I use the “cha-cha” method. I shift my weight(and hips) to one side, shoot a frame, then shift my weight to the other side, and shoot a frame. The shift distance is usually OK for normal scenes. A very rough rule of thumb is to shift the camera 1/30th of the distance to the nearest part of the scene. Click on the images to make them larger.
I know many many people can not manage the eye crossing thing. I’m sorry that you can not appreciate the images. Please indulge me, the effect when successfully viewed is striking and I love the extra (literally) dimension it brings to images.