a ULF pinhole camera with a storage bin UNDER the camera and a
storage compartment inside the camera and a sleeve.
you would be able to take exposed paper and slide it UNDER the camera,
and a fresh sheet of paper from inside the camera to "reload".
laser cut pinholes or zone plates are easy go get for close to exact exposures ..
and you can have an adjustment to lengthen or shorten the box so you have
the right "fixed" focal length you can hyperfocal if you want to use a "regular lens" ...