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[Concept]
Also known as the "TS" lens (the "TS" is the abbreviation of the English "Tilt & Shift", "tilt and shift"), oblique shot lens shift lens.
Is a reach adjustment for photography purpose like the perspective of the relationship or the region-wide focus camera lens.
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[Features]
(1) in the camera body and film plane location remain the same premise, so that the main optical axis of the cameras pan, tilt or rotate in order to achieve the purpose of adjustment of the photography like the perspective of the relationship or the region-wide focus.
2 axis camera lens of clear benchmarks field is much larger, in order to ensure that in the pan, tilt or rotate the camera lens light spindle can still get a clear image.
General photography the buildings are standing on the ground, in order to photograph the whole picture, the camera slightly upward Yang.
Building the lower part closer to the upper distant, shoot a "small" convergence.
The lens itself is not deformed, the reasons for this phenomenon is because the perspective of the relationship.
Remedy
The camera is shooting into the building.
This time may be the camera angle, the need for more wide-angle lens.
35 mm camera equivalent method with the same focal length but a greater perspective of the lens, and is on target shooting, will want to keep the film moved to scissor position (actually the lens in the opposite direction of translation).
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[For use]
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(1) to correct perspective distortion]
The following occurs when the top of the location when you're shooting from the building away from the building at the bottom of nearly the entire building like compressed, the roof also gathered together, there the building to collapse effect. If you put the shift lens, you can avoid this situation.
Shift lens can eliminate perspective distortion, because, in order to shoot the panoramic general shots of tall buildings, the lens need pitching. Results film plane with the main line of high-rise a certain angle, the smaller of the upper part of the object distance farther, resulting in perspective distortion.
Shift lens shift lens center through the film center on the film, the lower part of the distance to reach the center of the lens are not equal, although the upper part of the object distance farther, corresponding to the lower part of the image distance is farther, the magnification changes offset perspective deformation, as long as the film plane and parallel to the building the main line, make the photos there is no perspective distortion.
Equivalent to using a large format camera (such as 120 camera) shooting with a focal length lenses (wide angle), and then cut to 135 frame.
If we use ultra-wide-angle lens shooting, and then cut to enlarge the same effect as the shift lens, but can not take full advantage of the resolution.
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(2) adjust the focal plane position]
Depth of field control requires not only the lens shift function also requires that the lens swing function
The subject of a region-wide focus, the screen near and distant subject can form a clear image.
Under normal circumstances, the camera focal plane and film plane parallel to the shooting with a large aperture, the focal plane of the scene is clear - focus blur;
If the shift lens to adjust the focal plane, to change the clear point.
Shift plus swing, you can make an inclined plane focus to the focal plane, so that the inclined plane on the object image is clear.
This is not in the ordinary lens. Ordinary lens can only make clear the plane perpendicular to the axis of the lens focus.
The axis of the lens, these features are large plane only. These features not only require complex mechanical structure, also requires that the lens has a larger field of view, the greater the post-work space, shift lenses are expensive.
Because of the special mechanical structure, the shift lens in general there is no automatic aperture.
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[Use]
Mainly used for architectural photography and advertising photography.
Axis cameras are often used to shoot the region-wide focus was the screen.
Product advertising photography, commercial photography often this lens pan and tilt shooting combination of features in the correct subject perspective deformation, the normal camera lens is difficult to achieve region-wide focus effect.
Use more specialized, so the 135 axis of the lens itself is small, DX and film in this regard is also relatively small.
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【Article is excerpted from: Baidu Encyclopedia】
【Network reprint / Just reference】
【Translation is by Goolge】
