The Keyring Classic
The Keyring Classic is the latest version of the Pinhole Factory’s Brass exposure calculator. This can be used with any pinhole camera and any exposure meter to calculate how long the exposure is with pinhole camera or lens – it’s a must for all pinhole photographers. All you need to do is rotate the dial to your meter setting, then read off the exposure time by your pinhole aperture. The calculator also has a handy key ring so it can be attached to your camera case or a set of keys.