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Encyclopedia > Angle of view
A camera's angle of view can be measured horizontally, vertically, or diagonally.
A camera's angle of view can be measured horizontally, vertically, or diagonally.

In photography, angle of view describes the angular extent of a given scene that is imaged by a camera. It parallels, and may be used interchangeably with, the more general visual term field of view. Image File history File links Angle_of_view. ... Image File history File links Angle_of_view. ... Photography is the process of making pictures by means of capturing light on a light-sensitive medium, such as a sensor or film. ... An angle is the figure formed by two rays sharing a common endpoint, called the vertex of the angle. ... Large format camera lens. ... The field of view is the part of the observable world that is seen at any given moment. ...

Contents

Calculating a camera's angle of view

The angle of view of a camera is a function of three parameters:

  1. The dimensions of the film format or image sensor;
  2. The focal length of the photographic lens projecting the image; and
  3. The kind and degree of distortion of the lens.

It follows that for lenses projecting rectilinear (non-spatially-distorted) images, the film format or image sensor dimensions completely define the angle of view for any given lens focal length. // Movie film formats Amateur formats: 8 mm Single-8 Super 8 mm Polavision 9,5 mm film 17. ... Hello--80. ... The focal point F and focal length f of a positive lens, a negative lens, a concave mirror, and a convex mirror. ... 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... A distortion is the alteration of the original shape (or other characteristic) of an object, image, sound, waveform or other form of information or representation. ... In photography, a rectilinear lens is a photographic lens that yields images where straight features, such as the walls of buildings, appear with straight lines, as opposed to being curved. ... // Movie film formats Amateur formats: 8 mm Single-8 Super 8 mm Polavision 9,5 mm film 17. ... Hello--80. ...


Angle of view is usually measured one of three ways:

  • horizontally (from the left to right edge of the frame)
  • vertically (from the top to bottom of the frame)
  • diagonally (from one corner of the frame to its opposite corner)

For a lens projecting a rectilinear image, the angle of view (α) can be calculated from the chosen dimension (d), and effective focal length (ƒ)[1] thus:

alpha = 2 arctan frac {d} {2 f} [2]

Note that the effective focal length can simply be set equal to the stated focal length of the lens (F), except in macro photography where the magnification factor (m) must be taken into account: Soda bubbles in a glass — a macro photograph. ...

f = F cdot ( 1 + m )

If the chosen dimension is to be the diagonal, then it can be calculated from the horizontal and vertical dimensions of the format through the use of the Pythagorean Theorem: In mathematics, the Pythagorean theorem or Pythagoras theorem is a relation in Euclidean geometry among the three sides of a right triangle. ...

d = sqrt{h^2 + v^2}

where h is the horizontal dimension of the image format and v is its vertical dimension. For example, the diagonal measurement of the image format for a full-frame 35 mm camera is:

d = sqrt{36^2+24^2} = 43.27,mathrm{mm}

Lens types and effects

Lenses are often referred to by terms that express their angle of view:

  • Ultra wide-angle lenses, also known as fisheye lenses, cover up to 180° (or even wider in special cases)
  • Wide-angle lenses generally cover between 100° and 60°
  • Normal, or Standard lenses generally cover between 50° and 25°
  • Telephoto lenses generally cover between 15° and 10°
  • Super Telephoto lenses generally cover between 8° through less than 1°

Zoom lenses are a special case wherein the focal length, and hence angle of view, of the lens can be altered mechanically without removing the lens from the camera. Fisheye 15 mm (type: equisolid angle), 35 mm-film, cropped by slide-frame. ... One of Canons most popular wide-angle lenses - 17-40 mm f/4 L retrofocus zoom lens. ... In photography and cinematography, a telephoto lens is a lens whose focal length is significantly longer than the focal length of a normal lens. ... In photography and cinematography, a telephoto lens is a lens whose focal length is significantly longer than the focal length of a normal lens. ... A Canon Inc. ...


Longer lenses magnify the subject more, apparently compressing distance and (when focused on the foreground) blurring the background because of their shallower depth of field. Wider lenses tend to magnify distance between objects while allowing greater depth of field. An example of very shallow depth of field in a macro photograph. ...


Another result of using a wide angle lens is a greater apparent perspective distortion when the camera is not aligned perpendicularly to the subject: parallel lines converge at the same rate as with a normal lens, but converge more due to the wider total field. For example, buildings appear to be falling backwards much more severely when the camera is pointed upward from ground level than they would if photographed with a normal lens at the same distance from the subject, because more of the subject building is visible in the wide-angle shot. 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. ... In photography and cinematography a normal lens is a lens that generates images that are generally held to have a natural perspective compared with lenses with longer or shorter focal lengths. ...


Because different lenses generally require a different camera–subject distance to preserve the size of a subject, changing the angle of view can indirectly distort perspective, changing the apparent relative size of the subject and foreground. 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. ...

An example of how lens choice affects angle of view. The photos below were taken by a 35 mm camera at a constant distance from the subject.
28 mm lens
28 mm lens
50 mm lens
50 mm lens
70 mm lens
70 mm lens
210 mm lens
210 mm lens


Note that the angle of view of a given lens is frequently, and incorrectly, referred to as the angle of coverage, a term which describes the angle of projection by the lens onto the focal plane. Angle of coverage is only a consideration in technical photography involving view camera movements, in which the lens may be required to project an image circle much larger than the film dimensions. In cameras with fixed alignment between the lens and film (or sensor), it can generally be taken for granted that the center of the lens is aligned with the center of the frame, and the that image circle is large enough to cover the frame, and thus angle of coverage is not a consideration for the photographer. 135 Film Size, Kodak Tri-X 400 speed 135 (ISO 1007) is a film format for still photography. ... Image File history File links 1 of 4 photos shot to show different angle of view on various lenses. ... Image File history File links 1 of 4 photos shot to show different angle of view on various lenses. ... Image File history File links 1 of 4 photos shot to show different angle of view on various lenses. ... Image File history File links 1 of 4 photos shot to show different angle of view on various lenses. ... The view camera is a type of camera with a very long history (some modern examples are often mistaken for antiques), but they are still used today by professional and amateur photographers who want full control of their images. ...


A circular fisheye lens, as opposed to a full-frame fisheye, is an example of a lens where the angle of coverage has been narrowed relative to the other lenses in that system. In many cases the angle of view of the circular fisheye will be almost exactly the same as the nearest full-frame fisheye; however, the image projected onto the film is rendered circular because the diameter of the image projected is narrower than that needed to cover the widest portion of the film. Fisheye 15 mm (type: equisolid angle), 35 mm-film, cropped by slide-frame. ...


Common lens angles of view

This table shows the diagonal, horizontal, and vertical angles of view, in degrees, for lenses producing rectilinear images, when used with 36 mm × 24 mm format (that is, 135 film or full-frame 35mm digital[3]) 135 Film Size, Kodak Tri-X 400 speed 135 (ISO 1007) is a film format for still photography. ...

Focal Length (mm) 13 15 18 21 24 28 35 50 85 105 135 180 210 300 400 500 600 830 1200
Diagonal (°) 118 111 100 91.7 84.1 75.4 63.4 46.8 28.6 23.3 18.2 13.7 11.8 8.25 6.19 4.96 4.13 2.99 2.07
Vertical (°) 85.4 77.3 67.4 59.5 53.1 46.4 37.8 27.0 16.1 13.0 10.2 7.63 6.54 4.58 3.44 2.75 2.29 1.66 1.15
Horizontal (°) 108 100.4 90.0 81.2 73.7 65.5 54.4 39.6 23.9 19.5 15.2 11.4 9.80 6.87 5.15 4.12 3.44 2.48 1.72

Three-dimensional digital art

Displaying 3d graphics requires 3d projection of the models onto a 2d surface, and uses a series of mathematical calculations to render the scene. The angle of view of the scene is thus readily set and changed; some renderers even measure the angle of view as the focal length of an imaginary lens. The angle of view can also be projected onto the surface at an angle greater than 90°, effectively creating a fish eye lens effect. The rewrite of this article is being devised at Talk:3D computer graphics/Temp. ... This article or section does not adequately cite its references or sources. ...


Cinematography

Modifying the angle of view over time, or zooming, is a frequently used cinematic technique. It has been suggested that List of film techniques be merged into this article or section. ...


Video games

As an effect, some first person games, especially racing games, widen the angle of view beyond 90° to exaggerate the distance the player is travelling, thus exaggerating the player's perceived speed. This effect can be done progressively, or upon the activation of some sort of "turbo boost." An interesting visual effect in itself, it also provides a way for game developers to suggest speeds faster than the game engine or computer hardware is capable of displaying. Some examples include Burnout 3: Takedown and Grand Theft Auto: San Andreas. It has been suggested that this article or section be merged into Point of view shot. ... A game engine is the core software component of a computer or video game or other interactive application with real-time graphics. ... Computer hardware is the physical part of a computer, including the digital circuitry, as distinguished from the computer software that executes within the hardware. ... Grand Theft Auto: San Andreas is the fifth video game in the Grand Theft Auto series. ...


Players of first-person shooter games sometimes set the angle of view of the game, widening it in an unnatural way (a difference of 20 or 30 degrees from normal), in order to see more peripherally. This article or section does not cite its references or sources. ...


Notes

  1. ^ Calculations for lenses producing non-rectilinear images are much more complex and in the end not very useful in most practical applications.
  2. ^ Because this is a trigonometric function, the angle of view does not vary linearly with the focal length. That is why a small change in the focal length of wide angle lenses produces a greater change in the angle of view than the same change would produce in a telephoto lens.
  3. ^ However, most interchangeable lens digital cameras do not use 24x36 mm photosensors and therefore produce narrower angles of view than set out in the table. See subtopic Digital camera issues in the article on wide-angle lenses for further discussion.

One of Canons most popular wide-angle lenses - 17-40 mm f/4 L retrofocus zoom lens. ...

External links


  Results from FactBites:
 
Notes on The Gaze (944 words)
Kress and van Leeuwen argue that the horizontal angle adopted represents ‘whether or not the image-producer (and hence, willy-nilly, the viewer) is "involved" with the represented participants or not’ (Kress and van Leeuwen 1996, 143), with the frontal angle representing involvement and an oblique angle representing detachment.
Messaris notes that a low angle combined with a frontal view and a direct gaze at the viewer may be interpreted as overbearing, intimidating or menacing, and that when the intention is to use low angles to suggest noble or heroic qualities, side views are more common (Messaris 1997, 38).
In travel advertisements where there are rear views of people this tends to be either in longshots of landscapes or in midshots or close-ups of semi-naked bodies in seascapes (Messaris 1997, 24-7).
  More results at FactBites »

 
 

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