Normal lens
Encyclopedia
In photography
and cinematography
a normal lens, also called a standard lens, is a lens
that reproduces perspective that generally looks "natural" to a human observer under normal viewing conditions, as compared with lenses with longer or shorter focal lengths which produce an expanded or contracted field of view. Lenses of shorter focal length are called wide-angle lens
es, while longer-focal-length lenses are referred to as long-focus lens
es (with the most common of that type being the telephoto lens
es).
A lens with a focal length about equal to the diagonal size of the film or sensor format is known as a normal lens; its angle of view
is similar to the angle subtended by a large-enough print viewed at a typical viewing distance equal to the print diagonal; this angle of view is about 53° diagonally.
The term normal lens can also be used as a synonym for rectilinear lens
. This is a completely different use of the term.
s for photography are:
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 Oskar Barnack
, the creator of the Leica camera.
Note that the angle of view
depends on the aspect ratio
as well; a "normal" lens on 35mm does not have the same view as a "normal" lens on 645, for example.
, the sensor "type" is not the sensor diameter:
, a focal length
roughly equivalent to twice the diagonal of the image projected within the camera
is considered normal, since movies are typically viewed from a distance of about twice the screen diagonal.
Photography
Photography is the art, science and practice of creating durable images by recording light or other electromagnetic radiation, either electronically by means of an image sensor or chemically by means of a light-sensitive material such as photographic film...
and cinematography
Cinematography
Cinematography is the making of lighting and camera choices when recording photographic images for cinema. It is closely related to the art of still photography...
a normal lens, also called a standard lens, is a lens
Photographic lens
A camera lens is an optical lens or assembly of lenses used in conjunction with a camera body and mechanism to make images of objects either on photographic film or on other media capable of storing an image chemically or electronically.While in principle a simple convex lens will suffice, in...
that reproduces perspective that generally looks "natural" to a human observer under normal viewing conditions, as compared with lenses with longer or shorter focal lengths which produce an expanded or contracted field of view. Lenses of shorter focal length are called wide-angle lens
Wide-angle lens
From a design perspective, a wide angle lens is one that projects a substantially larger image circle than would be typical for a standard design lens of the same focal length; this enables either large tilt & shift movements with a view camera, or lenses with wide fields of view.More informally,...
es, while longer-focal-length lenses are referred to as long-focus lens
Long-focus lens
In photography, a long-focus lens is a camera lens which has a focal length that is longer than the diagonal measure of the film or sensor that receives its image....
es (with the most common of that type being the telephoto lens
Telephoto lens
In photography and cinematography, a telephoto lens is a specific type of a long-focus lens in which the physical length of the lens is shorter than the focal length. This is achieved by incorporating a special lens group known as a telephoto group that extends the light path to create a long-focus...
es).
A lens with a focal length about equal to the diagonal size of the film or sensor format is known as a normal lens; its angle of view
Angle of view
In photography, angle of view describes the angular extent of a given scene that is imaged by a camera. It is used interchangeably with the more general term field of view....
is similar to the angle subtended by a large-enough print viewed at a typical viewing distance equal to the print diagonal; this angle of view is about 53° diagonally.
The term normal lens can also be used as a synonym for rectilinear lens
Rectilinear lens
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. In other words, it is a lens with little or no barrel or pincushion distortion...
. This is a completely different use of the term.
Film still
Standard normal lenses for various film formatFilm format
A film format is a technical definition of a set of standard characteristics regarding image capture on photographic film, for either stills or movies. It can also apply to projected film, either slides or movies. The primary characteristic of a film format is its size and shape.In the case of...
s for photography are:
| Film format | Image dimensions | Image diagonal | Normal lens focal length |
|---|---|---|---|
| 9.5 mm Minox Minox The Minox is a subminiature camera conceived in 1922 and invented in 1936 by German-Latvian Walter Zapp, which Latvian factory VEF manufactured from 1937 to 1943. After World War II, the camera was redesigned and production resumed in Germany in 1948. Originally envisioned as a luxury item, it... |
8 × 11 mm | 13.6 mm | 15 mm |
| Half-frame | 24 × 18 mm | 30 mm | 30 mm |
| APS Advanced Photo System Advanced Photo System is a film format for still photography first produced in 1996. It was marketed by Eastman Kodak under the brand name Advantix, by FujiFilm under the name Nexia, by AgfaPhoto under the name Futura and by Konica as Centuria.- Design :The film is 24 mm wide, and has three... C |
16.7 × 25.1 mm | 30.1 mm | 28 mm, 30 mm |
| 135 135 film The term 135 was introduced by Kodak in 1934 as a designation for cartridge film wide, specifically for still photography. It quickly grew in popularity, surpassing 120 film by the late 1960s to become the most popular photographic film format... , 35mm |
24 × 36 mm | 43.3 mm | 45 mm, 50 mm |
| 120 120 film 120 is a film format for still photography introduced by Kodak for their Brownie No. 2 in 1901. It was originally intended for amateur photography but was later superseded in this role by 135 film... /220, 6 × 4.5 (645) |
56 × 42 mm | 71.8 mm | 75 mm |
| 120 120 film 120 is a film format for still photography introduced by Kodak for their Brownie No. 2 in 1901. It was originally intended for amateur photography but was later superseded in this role by 135 film... /220, 6 × 6 |
56 × 56 mm | 79.2 mm | 80 mm |
| 120 120 film 120 is a film format for still photography introduced by Kodak for their Brownie No. 2 in 1901. It was originally intended for amateur photography but was later superseded in this role by 135 film... /220, 6 × 7 |
56 × 68 mm | 88.1 mm | 90 mm |
| 120 120 film 120 is a film format for still photography introduced by Kodak for their Brownie No. 2 in 1901. It was originally intended for amateur photography but was later superseded in this role by 135 film... /220, 6 × 9 |
56 × 84 mm | 101.0 mm | 105 mm |
| 120 120 film 120 is a film format for still photography introduced by Kodak for their Brownie No. 2 in 1901. It was originally intended for amateur photography but was later superseded in this role by 135 film... /220, 6 × 12 |
56 × 112 mm | 125.0 mm | 120 mm |
| large format Large format Large format refers to any imaging format of 4×5 inches or larger. Large format is larger than "medium format", the 6×6 cm or 6×9 cm size of Hasselblad, Rollei, Kowa, Pentax etc cameras , and much larger than the 24×36 mm frame of 35 mm format.The main advantage... 4 × 5 sheet film Sheet film Sheet film is large format and medium format photographic film supplied on individual sheets of acetate or polyester film base rather than rolls. Sheet film was initially supplied as an alternative to glass plates... |
93 × 118 mm (image area) | 150.2 mm | 150 mm |
| large format Large format Large format refers to any imaging format of 4×5 inches or larger. Large format is larger than "medium format", the 6×6 cm or 6×9 cm size of Hasselblad, Rollei, Kowa, Pentax etc cameras , and much larger than the 24×36 mm frame of 35 mm format.The main advantage... 5 × 7 sheet film Sheet film Sheet film is large format and medium format photographic film supplied on individual sheets of acetate or polyester film base rather than rolls. Sheet film was initially supplied as an alternative to glass plates... |
120 × 170 mm (image area) | 208.0 mm | 210 mm |
| large format Large format Large format refers to any imaging format of 4×5 inches or larger. Large format is larger than "medium format", the 6×6 cm or 6×9 cm size of Hasselblad, Rollei, Kowa, Pentax etc cameras , and much larger than the 24×36 mm frame of 35 mm format.The main advantage... 8 × 10 sheet film Sheet film Sheet film is large format and medium format photographic film supplied on individual sheets of acetate or polyester film base rather than rolls. Sheet film was initially supplied as an alternative to glass plates... |
194 × 245 mm (image area) | 312.5 mm | 300 mm |
For a 35 mm
135 film
The term 135 was introduced by Kodak in 1934 as a designation for cartridge film wide, specifically for still photography. It quickly grew in popularity, surpassing 120 film by the late 1960s to become the most popular photographic film format...
camera
Camera
A camera is a device that records and stores images. These images may be still photographs or moving images such as videos or movies. The term camera comes from the camera obscura , an early mechanism for projecting images...
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 Oskar Barnack
Oskar Barnack
Oskar Barnack was a German optical engineer, precision mechanic, industrial designer and the father of 35mm photography....
, the creator of the Leica camera.
Note that the angle of view
Angle of view
In photography, angle of view describes the angular extent of a given scene that is imaged by a camera. It is used interchangeably with the more general term field of view....
depends on the aspect ratio
Aspect ratio
The aspect ratio of a shape is the ratio of its longer dimension to its shorter dimension. It may be applied to two characteristic dimensions of a three-dimensional shape, such as the ratio of the longest and shortest axis, or for symmetrical objects that are described by just two measurements,...
as well; a "normal" lens on 35mm does not have the same view as a "normal" lens on 645, for example.
Digital still
In digital photographyDigital photography
Digital photography is a form of photography that uses an array of light sensitive sensors to capture the image focused by the lens, as opposed to an exposure on light sensitive film...
, the sensor "type" is not the sensor diameter:
- (*) refers to TV tube diameters that were standards in the 50s. 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 | 4.0 × 3.0 mm | 5.0 mm | 5 mm |
| 1/3.2" | 7.9 mm | 4.5 × 3.4 mm | 5.7 mm | 5.7 mm |
| 1/3" | 8.5 mm | 4.8 × 3.6 mm | 6.0 mm | 6 mm |
| 1/2.7" | 9.4 mm | 5.4 × 4.0 mm | 6.7 mm | 6.7 mm |
| 1/2.5" | 10.2 mm | 5.8 × 4.3 mm | 7.2 mm | 7 mm |
| 1/2" | 12.7 mm | 6.4 × 4.8 mm | 8.0 mm | 8 mm |
| 1/1.8" | 14.1 mm | 7.2 × 5.3 mm | 8.9 mm | 9 mm |
| 1/1.7" | 14.9 mm | 7.6 × 5.7 mm | 9.5 mm | 9.5 mm |
| 2/3" | 16.9 mm | 8.8 × 6.6 mm | 11.0 mm | 11 mm |
| 1" | 25.4 mm | 12.8 × 9.6 mm | 16.0 mm | 16 mm |
| Four Thirds Four Thirds System The Four Thirds system is a standard created by Olympus and Kodak for digital single-lens reflex camera design and development.The system provides a standard that, with digital cameras and lenses available from multiple manufacturers, allows for the interchange of lenses and bodies from different... |
33.9 mm | 17.3 × 13 mm | 21.63 mm | 22 mm |
| 4/3" | 33.9 mm | 18.0 × 13.5 mm | 22.5 mm | 23 mm |
| APS-C | 45.7 mm | 22.7 × 15.1 mm | 27.3 mm | 27 mm |
| DX Nikon DX format The Nikon DX format is an alternative name used by Nikon corporation for APS-C image sensor format being approximately 24×16 mm. Its dimensions are about 2/3 those of the 35mm film format . The format was created by Nikon for its digital SLR cameras, many of which are equipped with DX-sized... |
n/a | 23.7 × 15.8 | 28.4 mm | 28 mm |
| FF (35 mm film) | n/a | 36 × 24 mm | 43.3 mm | 50 mm |
| (6 × 5 cm) | n/a | 49.0 × 36.7 mm | 61.2 mm |
Cinema
In cinematographyCinematography
Cinematography is the making of lighting and camera choices when recording photographic images for cinema. It is closely related to the art of still photography...
, a focal length
Focal length
The focal length of an optical system is a measure of how strongly the system converges or diverges light. For an optical system in air, it is the distance over which initially collimated rays are brought to a focus...
roughly equivalent to twice the diagonal of the image projected within the camera
Camera
A camera is a device that records and stores images. These images may be still photographs or moving images such as videos or movies. The term camera comes from the camera obscura , an early mechanism for projecting images...
is considered normal, since movies are typically viewed from a distance of about twice the screen diagonal.
| Film format | Image dimensions | Image diagonal | Normal lens focal length |
|---|---|---|---|
| Standard 8 8 mm film 8 mm film is a motion picture film format in which the filmstrip is eight millimeters wide. It exists in two main versions: the original standard 8mm film, also known as regular 8 mm or Double 8 mm, and Super 8... |
3.7 × 4.9 mm | 6.11 mm | 12–15 mm |
| Single-8 8 mm film 8 mm film is a motion picture film format in which the filmstrip is eight millimeters wide. It exists in two main versions: the original standard 8mm film, also known as regular 8 mm or Double 8 mm, and Super 8... (FUJI) |
4.2 × 6.2 mm | 7.5 mm | 15–17 mm |
| Super-8 Super 8 mm film Super 8 mm film is a motion picture film format released in 1965 by Eastman Kodak as an improvement of the older "Double" or "Regular" 8 mm home movie format.... |
4.2 × 6.2 mm | 7.5 mm | 15–17 mm |
| 9.5 mm 9.5 mm film 9.5 mm film is an amateur film format introduced by Pathé Frères in 1922 as part of the Pathé Baby amateur film system. It was conceived initially as an inexpensive format to provide copies of commercially-made films to home users, although a simple camera was released shortly afterwards.It... |
6.5 × 8.5 mm | 10.7 mm | 20 mm |
| 16 mm 16 mm film 16 mm film refers to a popular, economical gauge of film used for motion pictures and non-theatrical film making. 16 mm refers to the width of the film... |
7.5 × 10.3 mm | 12.7 mm | 25 mm |
| 35 mm 35 mm film 35 mm film is the film gauge most commonly used for chemical still photography and motion pictures. The name of the gauge refers to the width of the photographic film, which consists of strips 35 millimeters in width... |
18.0 × 24.0 mm | 30.0 mm | 60 mm |
| 35 mm 35 mm film 35 mm film is the film gauge most commonly used for chemical still photography and motion pictures. The name of the gauge refers to the width of the photographic film, which consists of strips 35 millimeters in width... , sound |
16.0 × 22.0 mm | 27.2 mm | 50 mm |
| 65 mm | |||
| 70 mm 70 mm film 70mm film is a wide high-resolution film gauge, with higher resolution than standard 35mm motion picture film format. As used in camera, the film is wide. For projection, the original 65mm film is printed on film. The additional 5mm are for magnetic strips holding four of the six tracks of sound... |
52.6 × 23.0 mm | 57.4 mm |