In photography and cinematography a normal lens is a lens that generates images that generally look "natural" to a human observer under normal viewing conditions as compared with lenses with longer or shorter focal lengths. Photography (fә'tɒgrәfi or fә'tɑːgrәfi (from Greek φωτο and γραφία is the process and Art of recording pictures by means of capturing See also Filmmaking Cinematography (from Greek: kinesis κινησις (movement and grapho γραφω (to record is the discipline A photographic lens (also known as objective lens or photographic objective) is an optical lens or assembly of lenses used in conjunction with Lenses of shorter focal length are called wide-angle lenses, while longer focal length lenses are often referred to as telephoto lenses.
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;[1] this angle of view is about 53 degrees diagonally. In Photography, angle of view describes the angular extent of a given scene that is imaged by a Camera.
Typical normal focal lengths for different formats
Standard normal lenses for various film formats for photography are:
| Film format | Image dimensions | Image diagonal | Normal lens focal length |
|---|---|---|---|
| 9. A film format is a technical definition of a set of standard characteristics regarding image capture on Photographic film, for either stills or movies 5 mm Minox | 8 × 11 mm | 13. Minox is the brand name of a Spy camera and Minox GmbH is the name of the company which produced them after World War II. 6 mm | 15 mm |
| APS C | 16. Advanced Photo System ( APS) is a Film format for still Photography. 7 × 25. 1 mm | 30. 1 mm | 28 mm, 35 mm |
| 135 | 24 × 36 mm | 43. 3 mm | 45 mm, 50 mm |
| 120/220, 6 × 4. 5 (645) | 56 × 45 mm | 71. 8 mm | 75 mm |
| 120/220, 6 × 6 | 56 × 56 mm | 79. 2 mm | 80 mm |
| 120/220, 6 × 7 | 56 × 68 mm | 88. 1 mm | 90 mm |
| 120/220, 6 × 9 | 56 × 84 mm | 101. 0 mm | 105 mm |
| large format 4 × 5 sheet film | 96 × 120 mm (image area) | 153. Large format describes large Photographic films large cameras View cameras (including Pinhole cameras and processes that use a film or digital sensor Sheet film is Large format and medium format Photographic film supplied on individual sheets of Acetate or Polyester Film base 7 mm | 150 mm |
| large format 8 × 10 sheet film | 194 × 245 mm (image area) | 312. Large format describes large Photographic films large cameras View cameras (including Pinhole cameras and processes that use a film or digital sensor Sheet film is Large format and medium format Photographic film supplied on individual sheets of Acetate or Polyester Film base 5 mm | 300 mm |
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. A camera is a device used to capture images either as still Photographs or as sequences of moving images ( Movies or Videos.
The 50 mm focal length was chosen by Oskar 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. Oskar Barnack ( November 1, 1879 – January 16, 1936) was a German precision Mechanic and industrial designer Leica Camera AG is a leading German optical company that has been designing and developing Cameras since 1913 and manufacturing them in series production since In Photography, acutance is the edge contrast of an image Acutance is related to the amplitude of the A lens is an optical device with perfect or approximate Axial symmetry which transmits and refracts Light, converging or diverging
In Digital photography, the sensor "type" is not the sensor diameter:
- (*) refers to tv-tube diameters that were standards in the 50's. Digital photography is a form of Photography that utilizes Digital technology to make Digital images of subjects 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 x 3. 0 mm | 5. 0 mm | 5 mm |
| 1/3. 2" | 7. 9 mm | 4. 5 x 3. 4 mm | 5. 7 mm | 5. 7 mm |
| 1/3" | 8. 5 mm | 4. 8 x 3. 6 mm | 6. 0 mm | 6 mm |
| 1/2. 7" | 9. 4 mm | 5. 4 x 4. 0 mm | 6. 7 mm | 6. 7 mm |
| 1/2. 5" | 10. 2 mm | 5. 8 x 4. 3 mm | 7. 2 mm | 7 mm |
| 1/2" | 12. 7 mm | 6. 4 x 4. 8 mm | 8. 0 mm | 8 mm |
| 1/1. 8" | 14. 1 mm | 7. 2 x 5. 3 mm | 8. 9 mm | 9 mm |
| 1/1. 7" | 14. 9 mm | 7. 6 x 5. 7 mm | 9. 5 mm | 9. 5 mm |
| 2/3" | 16. 9 mm | 8. 8 x 6. 6 mm | 11. 0 mm | 11 mm |
| 1" | 25. 4 mm | 12. 8 x 9. 6 mm | 16. 0 mm | 16 mm |
| 4/3" | 33. 9 mm | 18. 0 x 13. 5 mm | 22. 5 mm | 23 mm |
| (APS-C) | 45. 7 mm | 22. 7 x 15. 1 mm | 27. 3 mm | 27 mm |
| DX | n/a | 23. 7 x 15. 8 | 28. 4 mm | 28 mm |
| FF (35 mm film) | n/a | 36 x 24 mm | 43. A full-frame digital SLR is a Digital single-lens reflex camera (DSLR fitted with an Image sensor that is the same size as a 35 mm (36x24 mm film frame 3 mm | 50 mm |
| (4 x 5 cm) | n/a | 49. 0 x 36. 7 mm | 61. 2 mm |
In cinematography, 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. See also Filmmaking Cinematography (from Greek: kinesis κινησις (movement and grapho γραφω (to record is the discipline The focal length of an optical system is a measure of how strongly it converges (focuses or diverges (diffuses Light. A camera is a device used to capture images either as still Photographs or as sequences of moving images ( Movies or Videos.
| Film format | Image dimensions | Image diagonal | Normal lens focal length |
|---|---|---|---|
| N-8 | 3. 8 mm film is a motion picture film format in which the filmstrip is eight Millimeters wide 7 x 4. 9 mm | 6. 11 mm | 12 - 15 mm |
| Single - 8 (FUJI) | 4. 8 mm may refer to 8mm (band 8 mm film, or its replacement Super 8 mm film and Single-8 film 2 x 6. 2 mm | 7. 5 mm | 15 - 17 mm |
| Super - 8 | 4. Super 8 mm film, also simply called Super 8, is a motion picture film format released in 1965 by Eastman Kodak as an improvement of the 2 x 6. 2 mm | 7. 5 mm | 15 - 17 mm |
| 9.5 mm | 6. 95 mm film is an amateur Film format introduced by Pathé Frères in 1922 as part of the Pathé Baby amateur film system 5 x 8. 5 mm | 10. 7 mm | 20 mm |
| 16 mm, magnetical sound | 7. 5 x 10. 3 mm | 12. 7 mm | 25 mm |
| 16 mm, optical sound | |||
| 35 mm | 18. 35 mm film is the basic Film gauge most commonly used for both still Photography and Motion pictures, and remains relatively unchanged since its 0 x 24. 0 mm | 30. 0 mm | 60 mm |
| 35 mm, sound | 16. 35 mm film is the basic Film gauge most commonly used for both still Photography and Motion pictures, and remains relatively unchanged since its 0 x 22. 0 mm | 40. 5 mm | |
| 65 mm | |||
| 70 mm | 52. 70 mm film (or 65 mm film) is a wide high-resolution film gauge of superior quality to standard 35 mm motion picture film format. 70 mm film (or 65 mm film) is a wide high-resolution film gauge of superior quality to standard 35 mm motion picture film format. 6 x 23. 0 mm | 57. 4 mm |
See also
References
- ^ Leslie D. In Photography, angle of view describes the angular extent of a given scene that is imaged by a Camera. A photographic lens (also known as objective lens or photographic objective) is an optical lens or assembly of lenses used in conjunction with Stroebel (1999). View Camera Technique. Focal Press.
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