Converting an Old Slide Viewer Into a Usable Display

Thrift stores around the world have shelves littered with old slide projectors and slide viewers, as transparent slide technology is completely obsolete now. Don’t believe me? If you manage to find a film developer in your area, ask them to make some slides for you and observe the look on their face. And because millions upon millions of slide viewers were sold, they aren’t collectible or valuable. Still, it would be a shame if they all ended up in landfills, which is why Redditor ToBePacific converted a vintage slide viewer into a usable display.

Standard consumer slide viewers were very, very simple devices. A light bulb would shine through the slide and a magnifying viewing lens would let the user see the enlarged image. A fancy model might have some kind of mechanism for flipping through multiple slides.

For this project, ToBePacific was really only concerned with the nifty-looking enclosure and the viewing lens from a Hanimex Vista Viewer II 35mm slide viewer. By putting a small LCD inside the enclosure at the proper distance from the lens, the contents of the display would show up magnified. The magnification isn’t particularly strong, but it does enlarge the display a bit and gives it a unique slightly distorted appearance that has some vintage charm.

The LCD is 2”, but ToBePacific wasn’t pacific enough to specify details like the model or resolution. A Raspberry Pi Zero 2 W feeds video to that LCD and it can provide all kinds of information. ToBePacific programmed a custom script that pulls data from a bunch of different publicly accessible APIs and displays it. Using APIs from NASA, iNaturalist, and more, it shows weather information, asteroid sightings, notable upcoming astronomical events, and even little bits of trivia.

The modified slide viewer isn’t obtrusive and looks much cooler than something like a Facebook Portal, so ToBeSpecific can proudly place it on a desk or shelf and take a glance whenever he wants some information.