the precise, regularly-spaced sprocket holes on the edges of motion picture film. Together with teeth, which are accurately spaced on camera or projector sprockets, these holes control speed, registration, and synchronization of the film as it is propelled through a film camera or projector.
Regularly spaced and accurately shaped holes which are punched throughout the length of motion picture film. Pins, pegs and sprockets engage these holes as the film is transported through the camera, projector or other equipment.
These are the holes punched around the borders of the stamps to allow easy and convenient removal.
Regularly and accurately spaced holes punched throughout the length of film for still cameras. Basically the perforation function as a guide for precision registration of film and also provide mechanical movement from frame to frame.
The holes that are spaced along the length of the film in still cameras. The perforation function as a guide for precision registration of film and also assist with the mechanical movement from frame to frame.
Artificially made holes made in the tipping paper to allow ventilating air to enter the filter.
Holes punched between stamps in sheets to enable easy separation.
Holes through casing and cement into the productive formation.
Holes punched between stamps to make it easier for an individual to separate two or more stamps.
Holes formed by pins to make the separation of the stamps easier. Holes are almost all round but used is now being made of elliptical perforations in tandem with round perforations in some stamps.
Small hole at the page margins which sometimes occur as part of the manufacturing process. Not considered a defect. Perforations are sometimes used to tell if a comic is an unread copy. In such a copy tell-tale clicks are heard when the book is opened for the first time as the perforations separate.
Regularly spaced and accurately shaped holes which are punched throughout the length of a motion picture film. These holes engage the teeth of various sprockets and pins by which the film is advanced and positioned as it travels through cameras, processing machines, and projectors.
Air evacuation holes in a film made by pin perforators.
A series of holes that are stamped or drilled in the burner components to promote air flow.
Lines of small holes or cuts between rows of stamps that make them easy to separate.
Regularly and accurately spaced holes punched throughout the length of 35 mm film for still cameras.
Perforations are small holes that are punched into the edges of 35 mm film. They are punched with regular spacing so they can line up with sprockets that are in the camera's film take-up mechanism. When the perforations catch the sprockets the film can be forwarded and rewound.