 500 mm telephoto lens with extension tube. In photography and cinematography, a telephoto lens is a specific construction of a long focal length photographic lens that places its optical centre outside of its physical construction, such that the entire lens assembly is between the optical centre and the focal plane. A regular lens of a focal length that is longer than what is considered a normal lens is not necessarily a telephoto lens. A telephoto lens has to incorporate a special lens group known as a telephoto group (see below); nevertheless, non-telephoto lenses of long focal length are often informally referred to as telephoto lenses. The angle of view created by a telephoto lens is the same as that created by an ordinary lens of the same specified focal length. Image File history File links Large_format_camera_lens. ...
Image File history File links Size of this preview: 600 × 600 pixelsFull resolution (1500 × 1500 pixel, file size: 82 KB, MIME type: image/jpeg) 500mm Telephoto lens with extension tube taken by :) Dlohcierekim 22:35, 15 August 2006 (UTC). ...
Image File history File links Size of this preview: 600 × 600 pixelsFull resolution (1500 × 1500 pixel, file size: 82 KB, MIME type: image/jpeg) 500mm Telephoto lens with extension tube taken by :) Dlohcierekim 22:35, 15 August 2006 (UTC). ...
Photography [fәtɑgrәfi:],[foʊtɑgrәfi:] is the process of recording pictures by means of capturing light on a light-sensitive medium, such as a film or electronic sensor. ...
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Photographic lens One of Canons most popular wide angle lenses - 17-40 f/4 L The zoom lens of the Canon Elph A photographic lens (or more correctly, objective) is an optical lens or assembly of lenses used in conjunction with a camera body and mechanism to make images...
The cardinal points and the associated cardinal planes are a set of special points and planes in an optical system, which help in the analysis of its paraxial properties. ...
The focal plane of a lens is a plane that is perpendicular to the axis of the lens and passes through its focus. ...
The focal point F and focal length f of a positive (convex) lens, a negative (concave) lens, a concave mirror, and a convex mirror. ...
In photography and cinematography a normal lens is a lens that generates images that are generally held to have a natural perspective similar to human eyesight, compared with lenses with longer or shorter focal lengths. ...
A cameras angle of view can be measured horizontally, vertically, or diagonally. ...
Construction
Cross-section - typical telephoto lens. If a camera lens were to be constructed from a single lens of 200 mm focal length, then when the lens is focused on an object at infinity, the lens will be 200 mm away from the focal plane where the film or sensor is. The centre of the lens is referred to as the optical centre of the lens. Even constructing the lens out of multiple elements in the regular fashion, usually to eliminate aberrations, will still have the optical centre within the construction. Image File history File links No higher resolution available. ...
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Large format camera lens. ...
This article or section is in need of attention from an expert on the subject. ...
As the focal length of such lenses increases, the physical length of lens becomes inconveniently long. But such lenses are not telephoto lenses, no matter how extreme the focal length. They are simply known as long focal length lenses.
The diagram to the right shows the basic construction of a telephoto lens. It consists of front lens elements that, as a group, have a positive focus. The focal length of this group is shorter than the effective focal length of the lens. The converging rays from this group are intercepted by the rear lens group, sometimes called the "telephoto group," which has a negative focus. The simplest telephoto designs could consist of one element in each group, but in practice, more than one element is used in each group to correct for various aberrations. The combination of these two groups produces a lens assembly that is physically shorter than a long focus lens producing the same image size.
This same property is achieved with mirrors combined with lenses in catadioptric designs. The mirrors in such designs fold the light path and the curved secondary extends the light cone, making the lens much shorter than the focal length even given the folded design. However, lenses incorporating mirrors are not necessarily of telephoto design. Optical systems which involve both lenses and mirrors. ...
Compare with the opposite effect used in retrofocus lenses, sometimes described as inverted telephotos, which have greater clearance from the rear element to the film plane than their focal length would permit with a conventional wide-angle lens optical design. It is possible to construct zoom lenses that are telephotos at one extreme of the zoom range and retrofocus at the other. The Retrofocus photographic lens was invented in France in 1950 by Angenieux, and is characterized by a large negative meniscus lens element up front followed by four or five small elements in the rear. ...
One of Canons most popular wide-angle lenses - 17-40 mm f/4 L retrofocus zoom lens. ...
A Canon Inc. ...
The largest telephoto is made by Carl Zeiss and has a focal length of 1700 mm with a maximum aperture of f/4, implying a 425 mm (16.7 inch) entrance pupil. It is designed for use with a medium format Hasselblad 203 FE camera and weighs 256 kg (564 lb).[1] Carl Zeiss (September 11, 1816 – December 3, 1888) was an optician commonly known for the company he founded, Zeiss. ...
In an optical system, the entrance pupil is a virtual aperture that defines the area at the entrance of the system that can accept light. ...
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Hasselblad 503CW with Zeiss Distagon 3,5/30 and Ixpress V96C Hasselblad is a Swedish manufacturer of high-quality still photography cameras based in Gothenburg, Sweden. ...
Effects
Use of a telephoto lens will reduce perspective distortion of the subject and defocus the background, which is desirable in portrait photography. Telephoto and other long-focal-length lenses are best known for making distant objects appear magnified. This effect is similar to moving closer to the object, but is not the same, since perspective is a function solely of viewing location. Two images taken from the same location, one with a wide angle lens and the other with a telephoto lens, will show identical perspective, in that near and far objects appear the same relative size to each other. Comparing magnification by using a long lens to magnification by moving closer, however, the telephoto shot appears to compress the distance between objects due to the perspective from the more distant location. Long lenses thus give a photographer an alternative to the type of perspective distortion exhibited by shorter focal length lenses where (when the photographer stands closer to the given subject) different portions of a subject in a photograph can appear out of proportion to each other. Image File history File links Metadata Size of this preview: 399 × 599 pixelsFull resolution (633 × 950 pixel, file size: 126 KB, MIME type: image/jpeg) File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ...
Image File history File links Metadata Size of this preview: 399 × 599 pixelsFull resolution (633 × 950 pixel, file size: 126 KB, MIME type: image/jpeg) File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ...
Magnification is the process of enlarging something only in appearance, not physical size. ...
Perspective when used in the context of vision and visual perception refers to the way in which objects appear to the eye based on their spatial attributes or dimension and the position of the eye relative to the objects. ...
In photography and cinematography, a wide-angle lens is a lens whose focal length is shorter than the focal length of a normal lens. ...
In photography and cinematography, perspective distortion describes the appearance of a part of the subject as abnormally large, relative to the rest of the scene. ...
Long lenses also make it easier to blur the background more, even when the depth of field is the same; photographers will sometimes use this effect to defocus the background in an image to "separate" it from the subject.
Still photography Effect of different focal lengths on photographs taken from the same place: 28 mm Image File history File links 1 of 4 photos shot to show different angle of view on various lenses. ...
| 50 mm Image File history File links 1 of 4 photos shot to show different angle of view on various lenses. ...
| 70 mm Image File history File links 1 of 4 photos shot to show different angle of view on various lenses. ...
| 210 mm Image File history File links 1 of 4 photos shot to show different angle of view on various lenses. ...
| The above photos were taken using a 35 mm camera, using lenses of the given focal lengths. 135 Film Size, Kodak Tri-X 400 speed 135 (ISO 1007) is a film format for still photography. ...
The focal point F and focal length f of a positive (convex) lens, a negative (concave) lens, a concave mirror, and a convex mirror. ...
Constant object size The photographer often moves to keep the same image size on the film for a particular object. Observe in the comparison images below that although the foreground object remains the same size, the background changes size; thus, perspective is dependent on the distance between the photographer and the subject. The longer focus lenses compress the perception of depth, and the shorter focus exaggerate it.[2] The perspective of the so-called normal lens, 50mm focal length for 35 mm film format, is conventionally taken be a "correct" perspective, though a longer lens is usually preferred for a more correct perspective for portraits. 28 mm Image File history File links No higher resolution available. ...
| 50 mm Image File history File links No higher resolution available. ...
| 135 mm Image File history File links No higher resolution available. ...
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History The concept of the telephoto lens, in reflecting form, was first described by Johannes Kepler in his Dioptrice of 1611 [1], and re-invented by Peter Barlow in 1834. [2] Johannes Kepler (December 27, 1571 – November 15, 1630) was a German mathematician, astronomer and astrologer, and a key figure in the 17th century astronomical revolution. ...
Peter Barlow Peter Barlow (1776 - March 1, 1862) was an English writer on pure and applied mathematics. ...
Histories of photography usually credit Thomas Rudolphus Dallmeyer with the invention of the photographic telephoto lens in 1891, though it was independently invented by others about the same time; some credit his father John Henry Dallmeyer in 1860. [3] Thomas Rudolphus Dallmeyer (1859-1906), Anglo-German optician was the son of John Henry Dallmeyer who ran an optics business. ...
John Henry Dallmeyer (September 6, 1830 - December 30, 1883), Anglo-German optician, was born at Loxten, Westphalia, the son of a landowner. ...
See also // Movie film formats Amateur formats: 8 mm Single-8 Super 8 mm Polavision 9,5 mm film 17. ...
Secret photography involves a person or persons being unware that they are being intentionally photographed. ...
References - ^ The World's Largest Telephoto Lens. Press release.
- ^ Bill Smith (2001). Designing a Photograph: Visual Techniques for Making Your Photographs Work. Amphoto Books. ISBN 0817437789.
A press release (sometimes known as a news release or press statement) is a written or recorded communication directed at members of the news media for the purpose of announcing something claimed as having news value. ...
External links - Information on Catadioptric mirror lenses
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