The Sputnik creates side by side stereo pairs on 120 format film.
I scan the film and crop each frame to 1x1 square format, for the Sputnik. Next, I crop and spot each frame (in Photoshop), correct one of each pair for black and white point, exposure and contrast (in Lightroom). Then I copy and paste the exposure settings to the second image of the pair.
The magic occurs using Stereo Photo Maker, a free program. I import the two images, left and right, run the auto alignment utility and that gives me a viable stereo side-by-side pair, as long as I have followed the rules for taking the stereo picture in the first place (for example, foreground should not be too near, camera should be fairly horizontally inclined and so on). The stereo pair now can be printed and seen using my stereo viewer, a Brian May designed Owl Stereoscope. However, I prefer the old style stereo pictures in the Holmes stereo card format, which can also be viewed using the same device. So I use a tool in the SPM software to create the cards. The card size is 7 x 3.5 inches, the background is set to grey and the image to sepia. The SPM software is a very quirky vertical application with lots of options and settings, think Vuescan versus Epson Scan, for example, if you are familiar with those two. I have never been able to successfully print directly from SPM so I export the Holmes card image into a TIFF file and print from Potoshop.
Pretty surely, SPM isn't the only way of producing the card image but I don't know of any other.
