Add depth!

Stereoscopic imagery for everyone

Florian Haas

Playlists: 'froscon2021' videos starting here / audio

Stereoscopic imagery (photography and videography) is a fascinating way to create 3-dimensional images of landscapes, unmoving and moving objects, and of course, people.

In this talk, we'll cover the basics of stereoscopic imagery and projection, discover how stereoscopic vision works, and how we can trick our brains into perceiving depth from two flat images.

We start with the principles of three-dimensional vision in humans: how our eyes use the combination of focus and vergence to signal two slightly different images of our surroundings to our brain, and how our brain then processes these images to give us the perception of depth. Then, we discuss the techniques available to play tricks on our brains in which two slightly (but cleverly) distinct two-dimensional images are presented to our eyes in such a way that our mind conjures up depth where there objectively is none.

These techniques come in various forms, from very high tech (such as virtual reality goggles) to very low tech (like mechanical stereoscopic viewers), but some can deal without any projection technology at all: this is called freeviewing, and for most people it is a remarkably simple and low-cost way to enjoy stunning three-dimensional imagery. We'll cover the parallel-view and crossview freeviewing techniques.

We'll then dive into the simple but highly effective steps of making stereoscopic images, using run-of-the-mill cameras (even cell phones), and some straightforward image processing in the GIMP.

Finally, we talk about some neat little tricks to make stereoscopic videos, with minimal cost and investment. We'll look at how we can make 3D video with just a GoPro, or a simple drone camera — again using a free software tool, namely the Shotcut video editor, for processing.