淘宝上有个商家居然拿Scheimpflug principle忽悠人
现在哪个手电不是用的Scheimpflug原理聚光啊,JS会几个英文单词就拿出来忽悠人了。 {:1_257:}这个单词什么意思 不清楚 说说清楚啊 我还真不认识这个词。{:1_238:} 没明白 这个定律主要用于大画幅摄影 楼主继续,别成水贴啊 不认识 不明白,看不清 这个定律主要用于大画幅摄影funder 发表于 2009-11-12 10:01 http://www.shoudian.org/images/common/back.gif
google了下,似乎和单反上的移轴差不多回事情? 一般摄影焦平面和镜头平面是平行的,这要求被射物也在一个平面上才能清晰,这是沙曼定律的一种特殊情况。对于底片平面可以扭转的大画幅相机来说,可以通过底片平面的扭转,获得一个倾斜平面的清晰效果,这就是对沙曼定律的应用。 新手,直接不懂 楼主很小资 维基百科上解释的很详细啊。
The Scheimpflug principle is a geometric rule that describes the orientation of the plane of focus of an optical system (such as a camera) when the lens plane is not parallel to the image plane. It is commonly applied to the use of camera movements on a view camera. It is also the principle used in corneal pachymetry, the mapping of corneal topography, done prior to refractive eye surgery such as LASIK, and used for early detection of glaucoma. The principle is named after Austrian army Captain Theodor Scheimpflug, who used it in devising a systematic method and apparatus for correcting perspective distortion in aerial photographs.
Description of the Scheimpflug principle
Figure 1. With a normal camera, when the subject is not parallel to the image plane, only a small region is in focus.
Figure 2. The angles of the Scheimpflug principle, using the example of a photographic lens.
Figure 3. Rotation of the plane of focus.
Figure 4. Rotation-axis distance and angle of the PoF
Normally, the lens and image (film or sensor) planes of a camera are parallel, and the plane of focus (PoF) is parallel to the lens and image planes. If a planar subject (such as the side of a building) is also parallel to the image plane, it can coincide with the PoF, and the entire subject can be rendered sharply. If the subject plane is not parallel to the image plane, it will be in focus only along a line where it intersects the PoF, as illustrated in Figure 1.
When an oblique tangent is extended from the image plane, and another is extended from the lens plane, they meet at a line through which the PoF also passes, as illustrated in Figure 2 . With this condition, a planar subject that is not parallel to the image plane can be completely in focus.
Scheimpflug (1904) referenced this concept in his British patent; Carpentier (1901) also described the concept in an earlier British patent for a perspective-correcting photographic enlarger. The concept can be inferred from a theorem in projective geometry of Gérard Desargues; the principle also readily derives from simple geometric considerations and application of the Gaussian thin-lens formula, as shown in the section Proof of the Scheimpflug principle. 这个术语是德语啊
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