The producer (Peter Samuelson) saw two people standing on a corner holding a sign "looking for money for movie". Their story was used as a basic for the screenplay.
In the darkroom Ross takes a print directly from the developer and hangs it up without using the stop bath or fixer. When exposed to light, the print would turn black after several seconds.
While Jamie is at the table eating, Ross picks up a camera and takes several shots in a few seconds. The flash unit he is using is a Vivitar 283, which generally takes around 3 1/2 seconds to recycle after each shot.