Camera Parts: Take-up Spool
One of the key camera parts in a film camera is the take-up spool. This is a metal or plastic cylinder, generally located on the right side of the camera, looking from behind. There will be either a notch, gears or both on the cylinder.
Purpose of Take-up Spool
On film cameras, the take-up spool pulls the film along so unexposed film can be placed behind the shutter. Film attaches to either the notch or gears, allowing the spool to advance film as it turns.
Problems with the Take-up Spool
The main problems occur when the spool does not properly grip the film. Then, as the spool turns, the film is not pulled, and the same bit of film gets exposed over and over. A slipping grip is equally as bad, as the film will not advance completely, resulting in overlapping exposures. These occur due to improper loading or a damaged take-up spool.
Other problems can occur if moisture enters the take-up spool. Film can stick together, causing blurring or tears.
Special Take-up Spools
Most cameras pull film left to right, so exposed film is rolled around the take-up spool. Some cameras will actually wind all the film onto the take-up spool initially, then roll it back into the film cartridge as it is exposed. This is rare and only found in mechanically winding cameras, but it gives additional protection to the exposed film.