Hi Chris,
A classic method of making a "digital" camera I saw 20 odd years ago took a very small DRAM (well they all were then), in a ceramic package, smash the top off and then use the naked chip as a camera. They did this by refreshing the memory, then repeatedly scanning it and monitoring when the memory lost its "ones". Photoelectric effect discharged brightly lit pixels faster than dark ones.

I never made the camera, but I had a tidy little business in sixth form knocking off the lids and not breaking ANY of the angel hairs. I charged a tenner a time !

Steve