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Pan and scan is a method of adjusting widescreen film images so that they can be shown within the proportions of a standard definition 4:3 aspect ratio television screen, often cropping off the sides of the original widescreen image to focus on the composition's most important aspects. Some film directors and film enthusiasts disapprove of pan and scan cropping, because it can remove up to 45% of the original image on 2.35:1 films or up to 53% on earlier 2.55:1 presentations, changing the director or cinematographer's original vision and intentions. The worst examples remove up to 75% of the original picture on such aspect ratios as 2.75:1 or even 3:1 in epics such as ''Ben-Hur'', ''King of Kings'' or ''Lawrence of Arabia''. The vertical equivalent is known as "tilt and scan" or "reverse pan and scan". The method was most common in the days of VHS, before widescreen home media such as DVD and Blu-ray. Center cut is similar with the difference as the name suggests that it is simply a direct cut of the material from the center of the image with no horizontal panning or vertical tilting involved. This method doesn't require the permission or availability of the film maker or director to identify the most important part of each frame. Most video displays have three options for 16:9 widescreen frame formatting, which are either center cut, letterbox or full frame. The first two options are reliant on the video stream's aspect ratio flag being set correctly. ==Background== For the first several decades of television broadcasting, sets displayed images with a 4:3 aspect ratio in which the width is 1.33 times the height—similar to most theatrical films prior to 1960. This was fine for pre-1953 films such as ''The Wizard of Oz'' or ''Casablanca''. Meanwhile, in order to compete with television and lure audiences away from their sets, producers of theatrical motion pictures began to use "widescreen" formats such as CinemaScope and Todd-AO in the early to mid-1950s, which enable more panoramic vistas and present other compositional opportunities. Films with these formats might be twice as wide as a TV screen when televised. To present a widescreen movie on such a television requires one of two techniques to accommodate this difference: One is "letterboxing", which preserves the original theatrical aspect ratio, but is not as tall as a standard television screen, leaving black bars at the top and bottom of the screen; the other more common technique is to "pan and scan", filling the full height of the screen, but cropping it horizontally. Pan and scan cuts out as much as half of the image. In the 1990s (before Blu-ray Disc or HDTV), when so-called "Sixteen-By-Nine" or "Widescreen" televisions offered a wider 16:9 aspect ratio (1.78 times the height instead of 1.33), they allowed films made at 1.66:1 and 1.85:1 to fill most or all of the screen, with only small letterboxing or cropping required. DVD packaging began to use the expression, "16:9 – Enhanced for Widescreen TVs". However, films shot at aspect ratios of 2.20:1, 2.35:1, 2.39:1, 2.55:1, and especially 2.76:1 (''Ben-Hur'' for example) might still be problematic when displayed on televisions of any type. But when the DVD is "anamorphically enhanced for widescreen", or the film is telecast on a high-definition channel seen on a widescreen TV, the black spaces are smaller, and the effect is still much like watching a film on a theatrical wide screen. Though 16:9 (and occasionally 16:10, mostly for computers and tablets) remain standard as of 2012, wider-screen consumer TVs in 21:9 have been released to the market by multiple brands. 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「Pan and scan」の詳細全文を読む スポンサード リンク
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