That's neat. Wonder what the smallest pin hole diameter one could use, maybe .1 mm (.004 inch)? Just for kicks and giggles I built a 1 inch sq. drop bed camera that takes 13 X 13 mm images but uses a 25mm f3.5 lens from a Minolta 16mm camera. The lens has a slot for the aperture blades and I use brass shim stock with drilled holes for aperture control. Since there is no shutter I can only use paper because the only control I have over shutter speed is taking the lens cap off.