Homemade Matchbox Camera Shutter
Alan of alspix has come up with a nice a easy solution for creating a shutter to a pinhole camera - here is how he describes it (check out alspix blog for the most updated instructions):
Here's a couple of photos of the shutter I'm currently using. It's made from a couple of bits of scrap card. One has a quite large hole cut in the center which fits over the pinhole (I didn't cut this very neatly - you can do better!) The other piece acts as the shutter and slides behind this, covering the pinhole. I stuck some black tape on the back of this shutter card.
here is how it looks like:

You may also want to check out Matchbox Pinhole Camera and 35mm Sprocket Counter Clicker
check out alspix blog for the most updated instructions


