@thomasfuchs I worked for Pixera, which made digital cameras that were primarily used on microscopes. Worked on the Mac software, mostly, still PowerPC if I recall correctly.
the innovation of the camera was taking four images, shifted a half-pixel for 3 of them, getting an interpolated high resolution image.
@thomasfuchs Not sure if this qualifies as "obscure" but the first digital camera my family had was a Sony Mavica that wrote directly to 3½" floppy disks. Some of those old photos I took with it are still online, being served up by a PC my dad has been using as a webserver since around that same time period: http://www.bambi.net/eliot/a1.html
@thomasfuchs have you heard of the Cromenco Cyclops? It uses a decapsulated 1 kilobit DRAM chip as the image sensor and can be built from plans in Popular Electronics (Feb 1975). Here's a selfie at an astounding 32x32 pixels: