Angle of view

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In photography, angle of view (also called angle of coverage or field of view) is the amount of a given scene shown on the film or image sensor in photography; that is, there is generally much more to a scene visible to humans than shows up in photos, and various lenses record different degrees of the total image. There are also different ways to measure the angle of view:

horizontally
diagonally
vertically

Angle of view is affected by choice of lens:

Wide-angle lenses get considerably wider angle of view than telephoto lenses.
A fisheye lens records up to 180° of a scene (or sometimes a little more).
The longest lenses record less than 2° (e.g., a 1200mm lens on a 35mm camera has a horizontal viewing angle of 1°45′).

Longer lenses magnify the subject more, 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. One result of using a wide angle lens in proximity to the subject is an apparent perspective distortion: parallel lines may appear to converge and with a fisheye lens, straight edges will appear to bend.

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.

An example of how lens choice affects angle of view. 'The photos below were taken by a 35 mm camera.

28 mm lens

50 mm lens

70 mm lens

210 mm lens

*An example of how lens choice affects angle of view. 'The photos below were taken by a 35 mm camera.*
28 mm lens	50 mm lens
70 mm lens	210 mm lens

For a rectilinear lens (that is, a non-distorting, non-fisheye lens), the angle of view (α) can be calculated from the film or sensor dimension (d), and effective focal length (f) thus:

[\alpha = 2 \arctan \frac ]

The effective focal length can be set equal to the focal length of the lens (F), except in macro photography where the magnification (m) must be taken into account:

[f = F \cdot ( 1 + m )]

Common lenses angles of view

This table shows the diagonal, horizontal, and vertical angles of view in degrees of lenses when used with 24×36 mm format (that is, 135 film or full-frame 35mm digital).

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

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

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