Add depth! Stereoscopic imagery for everyone

Posted on Fri 06 November 2020 in talk-submissions

This is a talk I submitted1 to 2021. It was, unfortunately, rejected.

If you run a conference or meetup (on-person or online) where you think this talk would be a good fit, please let me know! I’d still love to present it when the opportunity arises.


Add depth! Stereoscopic imagery for everyone

Target Audience



This will appear in the conference programme. Up to about 500 words. This field is rendered with the monospace font Hack with whitespace preserved

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 OpenShot video editor, for processing.

Private Abstract

This will only be shown to organisers and reviewers. You should provide any details about your proposal that you don't want to be public here. This field is rendered with the monospace font Hack with whitespace preserved

This talk does not cover a specific software project; the "Project URL" below is simply a Flickr album containing a set of stereoscopic images created with the technique I am describing.

The fact that LCA is an online event this year would suit this talk particularly well: when I get to the point of explaining freeviewing to attendees, I would expect novices to have some difficulty with one of the freeviewing techniques, and some, with both. The latter would have the option of simply backing up the stream and re-watching the instructions and the test images provided, which is an option that would not exist in a live talk.

Accessibility note: Regretfully, this talk will have limited accessibility for people with vision deficiencies. Specifically, the 3D effects presented will be inaccessible to people with complete loss of vision in one eye (or both), nystagmus, or strabismus. People with these conditions will still be able to learn from the techniques presented in the talk, but will likely be unable to perceive the demonstrated 3D effects themselves. People with intraocular lens (IOL) implants might also have difficulty following some of the examples in the talk.

Project URL

  1. If you’re curious why this is here, please read this