8 mm film

8 mm film is a motion picture film format in which the film strip is eight millimeters wide. It exists in two main versions — the original standard 8 mm film, also known as regular 8 mm or Double 8 mm, and Super 8. Although both standard 8 mm and Super 8 are 8 mm wide, Super 8 has a larger image area because of its smaller and more widely spaced perforations.

There are also two other varieties of Super 8—Single 8 mm and Straight-8 that require different cameras, but produce a final film with the same dimensions.

The standard 8 mm (also known as regular 8) film format was developed by the Eastman Kodak company during the Great Depression and released to the market in 1932 to create a home movie format that was less expensive than 16 mm. The film spools actually contain a 16 mm film with twice as many perforations along each edge as normal 16 mm film; on its first pass through the camera, the film is exposed only along half of its width. When the first pass is complete, the operator opens the camera and flips and swaps the spools (the design of the spool hole ensures that the operator does this properly) and the same film is subsequently exposed along its other edge, the edge left unexposed on the first pass. After the film is developed, the processor splits it down the middle, resulting in two lengths of 8 mm film, each with a single row of perforations along one edge. Each frame is half the width and half the height of a 16 mm frame, so there are four times the number of frames in a given film area, which is what makes it cost less. Because of the two passes of the film, the format was sometimes called Double 8. The frame size of regular 8 mm is 4.8 mm × 3.5 mm and 1 meter of film contains 264 pictures. Normally Double 8 is filmed at 16 or 18 frames per second.

Common length film spools allowed filming of about 3 minutes to 4.5 minutes at 12, 15, 16 and 18 frames per second.

Kodak ceased sales of standard 8 mm film under its own brand in the early 1990s, but continued to manufacture the film, which was sold via independent film stores. Black-and-white 8 mm film is still manufactured in the Czech Republic, and several companies buy bulk quantities of 16 mm film to make regular 8 mm by re-perforating the stock, cutting it into 25 foot (7.6 m) lengths, and collecting it into special standard 8 mm spools, which they then sell. Re-perforation requires special equipment. Some specialists also produce Super 8 mm film from existing 16 mm, or even 35 mm film stock.

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