If you are standing in front of a high building with the camera, you have three options: In the classic case, the photographer directs his camera upwards and thus captures the entire building – but then there are dashed lines: upwards the house appears in the picture ever narrower . This can be corrected on the computer, but is additional work. If the photographer wants to avoid the falling lines at the time of shooting, he must aim at a point at eye level and thus obtain a correct picture. However, the upper part of the building is now cut off. The third solution is a shift lens: With shift lenses, the photographer can move the lens as a block against the bayonet, thus gaining an image section that is also shifted upwards.
An example: 24 mm lens on a vertically held full-format camera, distance to the house: 5 m, camera perspective: 1.75 above the ground. When the camera is horizontal, the house is mapped to a height of 5.50 m. With a lens cut by 8 mm, now 7.17 m are in the photo. However, all lenses show a more or less pronounced contrast reduction at the edges of the image. Shift lenses offer a larger picture circle, but how good is the edge really, if you shiftet by 8 mm, so consciously uses the edge area? Our test checks all candidates in the normal position and moves them by 8 mm.
In addition, all test candidates offer a tilt function. The photographer tilts the lens opposite the sensor plane and receives an oblique plane in the plane: In the normal case, an objective forms a plane parallel to the sensor plane. With freely selectable sharpness levels, especially studio or landscape photographers or architectural photographers work, in order to selectively "sharpen" the sharpness or obtain blurring (Scheimpflug).
In addition to Nikon and Canon, Hartblei offers Shift lenses in the United States. The German-Ukrainian coproduction is based exclusively on Zeiss optical components, so that problems with the antireflection, as they occurred at Walimex for example, are not an issue. All Hartblei optics are originally expected for the medium format and can therefore be used as a Shift or Tilt in KB format.
We have selected an APS-C and a full-size camera from Canon and Nikon. The shifted image of an APS-C camera should be sharp even in the corners with the aperture open. In the case of a full-format camera, only a dimmed image is likely to show a satisfactory corner contrast. For comparison, the diameters of the respective image circles in the case of a cross-format image and an 8-mm up-sharpened objective: Full format with / without shift: 43/54 mm, APS-C format with / without shift: 29/40 mm
No comments:
Post a Comment