@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:
@th @thomasfuchs
I remember a project to add digital video input to the BBC Micro, sometime in the 1980s, using this exact method.