Telephoto lens

In photography, a telephoto lens is a lens. There are two different uses of the word. The less specific use is to mean a lens that has a longer focal length than a normal lens. Their angle of view is smaller than that of a normal lens. With telephoto lenses things look closer than they really are.

The other meaning of telephoto lens applies to lenses that are constructed in a special way so they can be shorter than their focal length.

For 35 mm film, 50 mm is a normal focal length. Typical telephoto lenses are 85 mm (28°50') and 100 mm (24°). They are used for portraits mostly. Other telephoto lenses that are used often are 135 mm (18°), 180 mm and 200 mm. Many are zoom lenses.

Longer focal lengths (300 to 1200 mm) are used in sports and nature photography.

Different focal lengths

Effect of different focal lengths on photographs taken from the same place:

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  28 mm

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  50 mm

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  70 mm

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  210 mm

The above photos were taken using a 35 mm camera, using lenses of the given focal lengths.

Telephoto Lens Media

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  A collection of telephoto lenses

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  A 500 mm non-telephoto long lens with a physical length about the same as its focal length.

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  A 150–500 mm telephoto zoom lens, physically much shorter than its maximum focal length.

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  Diagram of a typical telephoto lens with a large positive lens and a smaller negative telephoto group combined to create a much longer focal length - f.

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  Diagram of a catadioptric mirrors lens.

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  A diagram of light travel through a wide-angle lens showing how focal length can be shorter than the lens.

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  A Canon New F-1 (1981), a 35 mm camera with a telephoto zoom lens with 70-210 mm focal length.

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  Compact digital cameras like the Panasonic Lumix DMC-TZ18 (2010) typically have superzoom lenses with large focal length. The lens is completely stored inside the camera in switched-off state and has a maximum focal length (shown) of 384 mm (calculated equivalent to 35 mm film), minimum is 24 mm, a factor of 16.