Sure it is a cheap stage trick, but using a lenticular lens at the right angle and in front of the right background can render what’s behind it invisible. That’s not news, but [Ian] spent some time investigating how to make the best one he could. His instructions cover how to create your own with polycarbonate, the right lens, and some optically clear adhesive. You can see some details about the shield along with some demonstrations in the video below.
The first iteration of the design worked, but it had some distracting lines and curvatures. The second version uses a large sheet of polycarbonate and liquid adhesive to attach the lens. It looks much better.
The effect works best when you have a bold horizontal pattern behind you and, of course, only works from certain sight angles. Even then, you can see when [Ian] is moving behind the shield, but it is pretty muted. However, the final version did look better even though UV curing that big sheet of plastic looked painful.
The final few minutes of the video shows some real world user testing that looked like a lot of fun. There are other ways to bend light to get limited invisibility. We’ve seen these lenses used for faux holograms, too.