I made a pinhole camera with a cigar box and Polaroid filmback (665 film). The 0.3mm aperture is bored through a sheet of brass, colored black to minimize internal reflections.
Due to reciprocity failure, exposures are quite long. Even in full daylight, 15 seconds is typical.
When using color film, it is necessary to shoot through heavy yellow and orange filters.
It makes photographs like these.
Here is the camera.
Calculating aperture to film, it’s an f/318, though that designation doesn’t really make much sense. Still, it sounds good.