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__NOTOC__ In photography, headroom or head room is a concept of aesthetic composition that addresses the relative vertical position of the subject within the frame of the image. Headroom refers specifically to the distance between the top of the subject's head and the top of the frame, but the term is sometimes used instead of lead room, nose room or 'looking room'〔Thompson, Roy. (''Grammar of the shot'' ), Focal Press, 1998, p. 64. ISBN 0-240-51398-3〕 to include the sense of space on both sides of the image. The amount of headroom that is considered aesthetically pleasing is a dynamic quantity; it changes relative to how much of the frame is filled by the subject. One rule of thumb taken from classic portrait painting techniques,〔Hurter, Bill. (''The Best of Portrait Photography: Techniques and Images from the Pros'' ), Amherst Media, Inc, 2003, p. 38. ISBN 1-58428-101-4〕 called the "rule of thirds",〔(''Camera Terms'' ), Retrieved on June 25, 2009.〕〔MediaCollege.com. (''Framing'' ), Retrieved on June 25, 2009.〕 suggests that the subject's eyes, as a center of interest, are ideally positioned one-third of the way down from the top of the frame.〔Barbash, Ilisa; Taylor, Lucien. (''Cross-cultural Filmmaking: A Handbook for Making Documentary and Ethnographic Films and Videos'' ), University of California Press, 1997, p. 97. ISBN 0-520-08760-7〕 Moving images such as movie cameras and video cameras have the same headroom issues as still photography, but with the added factors of the movement of the subject, the movement of the camera, and the possibility of zooming in or out. Perceptual psychological studies have been carried out with experimenters using a white dot placed in various positions within a frame to demonstrate that observers attribute potential motion to a static object within a frame, relative to its position. The unmoving object is described as 'pulling' toward the center or toward an edge or corner.〔Ward, Peter. (''Picture composition for film and television'' ), Elsevier, 2003, p. 84. ISBN 0-240-51681-8〕 Proper headroom is achieved when the object is no longer seen to be slipping out of the frame—when its potential for motion is seen to be neutral in all directions. Headroom changes as the camera zooms in or out, and the camera must simultaneously tilt up or down to keep the center of interest approximately one-third of the way down from the top of the frame.〔 The closer the subject, the less headroom needed.〔Millerson, 1994, p. 80.〕 In extreme close-ups, the top of the head is out of the frame,〔 but the concept of headroom still applies via the rule of thirds. In television broadcast camera work, the amount of headroom seen by the production crew is slightly greater than the amount seen by home viewers, whose frames are reduced in area by about 5%.〔 To adjust for this, broadcast camera headroom is slightly expanded so that home viewers will see the correct amount of headroom.〔 Professional video camera viewfinders and professional video monitors often include an overscan setting to compare between full screen resolution and "domestic cut-off"〔 as an aid to achieving good headroom and lead room. One of the most common mistakes that casual camera users make is to have too much headroom: too much space above the subject's head.〔Trem.ca, digital photography. (''Basic Rules of Photography'' ), Retrieved on June 25, 2009.〕 ==Examples== File:Too much headroom.png|A portrait of guitarist Adrian Legg demonstrates an excessive amount of headroom, with the subject's nose centered in the frame (a common mistake.) File:Not enough headroom.png|A subtle lack of headroom with the subject's eyes only 28% of the way down from the top, not 33% File:Correct headroom.png|Good composition, with the subject's eyes one-third of the distance down from the top of the frame, following the rule of thirds File:Correct headroom with zoom grid.png|For moving images, the action of zooming in to fill the frame with the subject requires the simultaneous tilting up of the camera, shown by the red lines, to maintain the correct amount of headroom. Conversely, zooming out requires tilting down. 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「Headroom (photographic framing)」の詳細全文を読む スポンサード リンク
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