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Standard 8 mm film, also known as Regular 8 mm film, Double 8 mm film, Double Regular 8 mm film, or simply as Standard-8 or Regular-8, is a film format originally developed by the Eastman Kodak company and released onto the market in 1932. ==History== The format, initially known as ''Cine Kodak Eight'', was developed by Kodak to provide a cheaper and more portable alternative to the 16 mm film format introduced a decade earlier. Standard 8 mm film stock consists of 16 mm film reperforated to have twice the usual number of perforations along its edges, though using the same size sprocket holes. This film is run through the camera, exposing one edge of the film only (the frame size of standard 8 mm film is 4.8 mm x 3.5 mm). The spool is then reversed and the film run through again, exposing the other edge. After processing the film is cut down the centre and spliced together to give one roll of 8mm wide film. The standard spool size for amateur use contains 25 ft of film, giving a total of 50 ft available for projection; at the usual filming speed of 16 frames per second this gives about four minutes of footage.〔http://www.gcmstudio.com/filmspecs/filmspecs.html〕 The format was an immediate success, but retains a number of inherent problems and quirks, mostly connected with the fact that the spool needs to be removed and reversed half way through filming. This procedure is tricky for the inexperienced user and needs to be carried out in subdued light to avoid fogging of the edges of the film. In addition, the central six feet of the finished film includes a characteristic burst of light corresponding to the reversal point (unless the film is again edited and spliced). In the early 1960s, a new filming and projection standard of 18 frames per second was introduced, although many cameras and projectors included a multi-speed facility. The standard 8 mm format was quickly displaced, for the most part, by the Super 8 mm film format - which offers cartridge loading, a 50% larger frame size and electric-powered cameras - from the mid-1960s onwards. Super 8 was often erroneously criticized, since the film gates in some cheaper Super 8 cameras were plastic, as was the pressure plate built into the cartridge; the standard 8 cameras had a permanent metal film gate that was regarded as more reliable in keeping the film flat and the image in focus. In reality, this was not the case. The plastic pressure plate could be moulded to far smaller tolerances than their metal counterparts could be machined. More sophisticated standard 8 mm cameras permit backwind of the film - difficult but not impossible with a Super 8 cartridge - enabling simple double-exposure and dissolve effects to be made in-camera. Super 8's smaller sprocket holes, while allowing a larger frame size, were also inherently more liable to tear. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Standard 8 mm film」の詳細全文を読む スポンサード リンク
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