I've been experimenting with pinhole photography, and I wanted to mount my pinholes on a tripod.  I found that the standard tripod screw mount is ¼"-20 UNC, so that is what I used.  I have made a bunch of different cameras from different things including a ramen container, until I saw something in my own hand.  I created a cap for the can at 66mm, and if you have a dark bag, you can change out your ‘film’ and shoot over and over.  There is a great pinhole camera calculator here that I used to figure out pinhole diameters etc.

I opened the can with a normal can opener to reveal a rounded over 52mm aperture.

NB, I would paint the cap on the inside with black paint, as my filament was translucent when printed.