The Game Boy first arrived in 1989, but it took nearly a decade for the Game Boy Camera to arrive. Cameras wouldn't become commonplace in phones for several years, and here was Nintendo leading the charge to mobile photography in a multipurpose device.
But it was terrible. The Game Boy Camera could only take 0.1 MP photos, was only useful in a well-lit room, and could only store 30 photos at a time. Worse, it couldn't actually transfer those photos digitally. Your only option was to print the photos from a tiny dot-matrix printer that produced images about the size of a postage stamp.
Why anyone would want to attach a DSLR to the Game Boy Camera is beyond me, but that's exactly what Australian YouTuber Conorsev did last month. First, he disassembled the Game Boy Camera so he could solder the connectors to an Arduino chip in order to download photos digitally. After that, the Game Boy Color's lens was replaced with a Cannon DSLR that let him take extremely clear photos with a powerful zoom.
Of course, the Game Boy Camera sensor still only takes 0.1 MP images, so it doesn't matter how large and clear the lens is, you're still getting a dot-matrix image the size of a stamp. On the plus side, you'll get a sturdy place to grip your Game Boy, so there's that.
Besides the Arduino chip and some custom code, you'll need a special adaptor for the Cannon DSLR, which you can print from a 3D printer. Instructions for both can be found in the video description.
To further improve the displayed image, Conorsev also upgraded his original Game Boy with a true LCD in place of the dot matrix screen. This mod makes playing GTA5 on the Game Boy a whole lot easier.