A changing bag is probably the most essential piece of equipment a photographer can carry, and it is also one of the most simple. Having a changing bag to hand means that a jammed or partly exposed film can be safely removed from the camera and shooting can continue and it will allow a film to be loaded into a developing tank without having to first find a darkroom. The Paterson changing bag is small enough to fit into a camera bag, yet large enough to allow a camera back to be fully opened once inside or a film to be loaded into a tank. It has a fail-safe double skin with a double zip closure and the inner lining is specially designed to avoid perspiration in prolonged use.