Francais | English | Espanõl

Normal lens

From Wikipedia, the free encyclopedia

Jump to: navigation, search

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.

Lenses of shorter focal length are called wide-angle lenses, while longer focal length lenses are called telephoto lenses.

In still photography, a normal lens is a lens whose focal length is roughly equivalent to the diagonal of the image projected within the camera. This roughly approximates the perspective perceived by the human vision.

  • Standard normal lenses for various film formats for photography are:


Film format Image dimensions Image diagonal Normal lens focal length
APS C 16.7 × 25.1 mm 30.15 mm 28 mm, 35 mm
135 24 × 36 mm 43.27 mm 50 mm, 45 mm
120/220, 6 × 4.5 (645) 56 × 45 mm 71.84 mm 75 mm
120/220, 6 × 6 56 × 56 mm 79.20 mm 80 mm
120/220, 6 × 7 56 × 68 mm 88.09 mm 90 mm
120/220, 6 × 9 56 × 84 mm 100.96 mm 105 mm
large format 4 × 5 sheet film 101.6 × 127 mm (4 × 5") 162.64 mm 150 mm
large format 8 × 10 sheet film 203.2 × 254 mm (8 × 10") 325.27 mm 355 mm (14")

For a 35 mm camera with a diagonal of 43 mm, the most commonly used normal lens is 50 mm, but focal lengths between about 40 and 58 mm are also considered normal.

The 50 mm focal length was chosen by Oscar Barnack, the creator of the Leica camera, as a compromise between the theoretical value and good sharpness, as lens technology at the time was such that slightly longer focal lengths were able to achieve optimum sharpness.


  • In Digital photography the situation is more complex. The sensor type diameter is not the sensor diameter:
(*) refers to tv-tube diameters that were standards in the 50's. The normal lens focal length is roughly 2/3 of the TV tube diameter.
(**) this is a mathematical calculation because most of the cameras are equipped with zoom lenses.
Sensor type TV-tube diameter * Image dimensions Image diagonal Normal lens focal length **
1/3.6" 7.1 mm 4.00 x 3.00 mm 5.00 mm 5 mm
1/3.2" 7.9 mm 4.54 x 3.42 mm 5.68 mm 5.7 mm
1/3" 8.5 mm 4.80 x 3.60 mm 6.00 mm 6 mm
1/2.7" 9.4 mm 5.37 x 4.04 mm 6.72 mm 6.7 mm
1/2.5" 10.2 mm 5.76 x 4.29 mm 7.2 mm 7 mm
1/2" 12.7 mm 6.40 x 4.80 mm 8.00 mm 8 mm
1/1.8" 14.1 mm 7.18 x 5.32 mm 8.93 mm 9 mm
1/1.7" 14.9 mm 7.60 x 5.70 mm 9.50 mm 9.5 mm
1/1.6" 15.9 mm 10.5 mm
2/3" 16.9 mm 8.80 x 6.60 mm 11.00 mm 11 mm
1" 25.4 mm 12.80 x 9.60 mm 16.00 mm 16 mm
4/3" 33.9 mm 18.00 x 13.50 mm 22.50 mm 23 mm
(APS-C) 1/8" 45.7 mm 22.70 x 15.10 mm 27.3 mm 27 mm
DX n/a 23.7 x 15.8 28.40 mm 28 mm
FF (35 mm film) n/a 36 x 24 mm 43.30 mm 50 mm
(4 x 5 cm) n/a 49.0 x 36.7 mm 61.22 mm



Film format Image dimensions Image diagonal Normal lens focal length
N-8 3.68 x 4.88 mm 6.11 mm 12 - 15 mm
Single - 8 (FUJI) 4.22 x 6.24 mm 7.53 mm 15 - 17 mm
Super - 8 4.22 x 6.24 mm 7.53 mm 15 - 17 mm
9.5 mm 6.5 x 8.5 mm 61.61 mm 120 mm
16 mm, magnetical sound 7.49 x 10.26 mm 12.70 mm 25 mm
16 mm, optical sound
35 mm 18.00 x 24.00 mm 30.00 mm 60 mm
35 mm, sound 16.03 x 22.05 mm 40.53 mm
65 mm
70 mm 52.6 x 23.0 mm 57.41 mm


See also: angle of view, photographic lens.da:Normalobjektiv de:Normalobjektiv eo:Normala objektivo pl:Obiektyw standardowy ru:Нормальный объектив sv:Normalobjektiv zh:标准镜头

Retrieved from "http://en.wikivisual.com/index.php/Normal_lens"
Personal tools