Quick update, I shot a roll over the weekend with the smallest hole I could make using a pin, estimated 0.25mm and I got some reasonable shots out in Gunnersbury Park and at train stations. Not razor sharp by any means but decent images. now the problem seems to be some minor light reflections within the camera, probably from the aluminium foil used to make the pinhole. But for what it cost, as an exercise in proving that pinhole photography works....it's quite good. I agree a little hacking could make a better camera. Given it's aimed at kids, actually the fact that it's very simple and can yield decent results is great.