Thursday, June 12, 2008
what is the perspektif in photography
In photography, a perspective correction lens (also known as a PC lens, perspective control lens, or shift lens, or — if the lens can also tilt — a tilt and shift or TS lens) allows the photographer to correct for the effects of perspective by shifting the lens in relationship to the film or sensor area. This type of lens is mostly used in architectural and other technical photography. Perspective control lenses are generally made for single-lens reflex (SLR) 35 mm and medium-format SLR cameras, as most large format cameras allow for perspective correction using movements.
A perspective control lens has a larger image circle than is required to cover the image area (film or sensor size). Typically, the image circle is large enough, and the mechanics of the lens sufficiently limited, that the film plane cannot be shifted outside of the image area. However, all PC lenses require a small aperture setting to prevent vignetting when significant shifts are employed. PC lenses for 35 mm cameras typically offer a maximum shift of 11 mm.
The first PC lens manufactured for an SLR camera in any format was Nikon's 1961 f/3.5 PC-Nikkor. It was followed by an f/2.8 35 mm PC-Nikkor and an f/3.5 28 mm PC-Nikkor. Other manufacturers, including Olympus, Pentax, Schneider Kreuznach (produced as well for Leica), and Minolta, made their own versions of PC lenses. Olympus produced a 35 mm shift lens and a 24 mm shift lens. Canon produce 24 mm, 45 mm, and 90 mm TS lenses.
A perspective control lens has a larger image circle than is required to cover the image area (film or sensor size). Typically, the image circle is large enough, and the mechanics of the lens sufficiently limited, that the film plane cannot be shifted outside of the image area. However, all PC lenses require a small aperture setting to prevent vignetting when significant shifts are employed. PC lenses for 35 mm cameras typically offer a maximum shift of 11 mm.
The first PC lens manufactured for an SLR camera in any format was Nikon's 1961 f/3.5 PC-Nikkor. It was followed by an f/2.8 35 mm PC-Nikkor and an f/3.5 28 mm PC-Nikkor. Other manufacturers, including Olympus, Pentax, Schneider Kreuznach (produced as well for Leica), and Minolta, made their own versions of PC lenses. Olympus produced a 35 mm shift lens and a 24 mm shift lens. Canon produce 24 mm, 45 mm, and 90 mm TS lenses.
colllect from wikkipedia
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