My brother has a small collection of stereo picture cards and a wooden viewer. They are just incredible to use and see, when the image is clear and the focused image depth was good. I had always shied away from stereo cameras but might look into it again. I have seen some creative applications of it with scanned images to create a flickering animated 3d image. It's so much easier to adjust your eye to them than using the old wood and glass viewers. I have even seen results from from cameras that take more than 2 frames such as the nimslo, applied digitally that seemed to have even more depth to the image. The Nypl took on a monumental task of scanning their entire stereo picture collection and made it available online to edit into animated flickering 3d images. They did a good job and I suggest that people take a look at it if they have a bit of time. It's called the stereograminator.
I think I'll have to pick up a stereo realist for the summer and really give it a try.