Lens speed

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A fast prime (fixed focal length) lens, the Canon 50mm
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f/1.4 (left), and a slower zoom lens, the Canon 18-55mm
f/3.5-5.6 (right); this lens is faster at 18mm than it is at 55mm. Lensspeed.jpg
A fast prime (fixed focal length) lens, the Canon 50mm f/1.4 (left), and a slower zoom lens, the Canon 18–55mm f/3.5–5.6 (right); this lens is faster at 18mm than it is at 55mm.

Lens speed is the maximum aperture diameter, or minimum f-number, of a photographic lens. A lens with a larger than average maximum aperture (that is, a smaller minimum f-number) is called a "fast lens" because it can achieve the same exposure as an average lens with a faster shutter speed. Conversely, a smaller maximum aperture (larger minimum f-number) is "slow" because it delivers less light intensity and requires a slower (longer) shutter speed.

Contents

A fast lens speed is desirable in taking pictures in dim light, for stability with long telephoto lenses, and for controlling depth of field and bokeh, especially in portrait photography, [1] as well as for sports photography and photojournalism.

Lenses may also be referred to as being "faster" or "slower" than one another; so an f/3.5 lens can be described as faster than an f/5.6 despite f/3.5 not generally being considered "fast" outright. What is considered fast largely depends on focal length, image diameter (i.e. format covered, such as APS, full frame, medium format), and in the case of zoom lenses, zoom factor.

Tradeoffs

Three 50 mm prime lenses from Minolta with lens speed 3.5 (a macro photography lens, speed of less priority), 1.7 (standard), and 1.2 (large opening and high speed, typically expensive), showing the relation between entry lens diameter and lens speed. Three Minolta 50 mm photographic lenses with different lens speeds of 3.5, 1.7, and 1.2.jpg
Three 50 mm prime lenses from Minolta with lens speed 3.5 (a macro photography lens, speed of less priority), 1.7 (standard), and 1.2 (large opening and high speed, typically expensive), showing the relation between entry lens diameter and lens speed.

Attaining maximum lens speed requires engineering tradeoffs, and as such, "prime" (fixed focal length) lenses are generally faster than zoom lenses. [2]

With 35mm film cameras and full-frame digital cameras, the fastest lenses are typically in the "normal lens" range near 50mm; here, there are several relatively inexpensive high-quality fast lenses available. For example, the Canon EF 50mm f/1.8 II or Nikon AF Nikkor 50mm f/1.8D are very inexpensive, but quite fast and optically well-regarded. Old fast manual focus lenses, such as the Nikkor-S(C) or Nikkor AI-S 50mm f/1.4, or Canon's FD and M39 counterparts, were historically produced abundantly, and are thus sold relatively inexpensively on the used lens market.

Especially outside of the "normal" focal length, lens speed also tends to correlate with the price and/or quality of the lens. This is because lenses with larger maximum apertures require greater care with regard to design, precision of manufacture, special coatings and quality of glass. At wide apertures, spherical aberration becomes more significant and must be corrected. Thus, faster telephoto and wide-angle retrofocus designs tend to be much more expensive.

A telecompressor, also known as a speed booster, may be used to increase the speed of a lens with a corresponding reduction to its focal length. For example, the Metabones 0.58x BMPCC speed booster may be combined with a f/1.2 lens to produce f/0.74. [3]

Fast lenses

While the fastest lenses in general production in the 2010s were f/1.2 or f/1.4, the 2020s have seen several f/0.95 lenses, see below.

What is considered "fast" has evolved to lower f-numbers over the years, due to advances in lens design, optical manufacturing, quality of glass, optical coatings, and the move toward smaller imaging formats. For example, the 1911 Encyclopædia Britannica states that "...[Lenses] are also sometimes classified according to their rapidity, as expressed by their effective apertures, into extra rapid, with apertures larger than f/6; rapid, with apertures from f/6 to f/8; slow, with apertures less than f/11" whilst today, f/6 would be deemed at the rather slow end.

Canon 85mm
f/1.8 and
f/1.2 showing their large entrance pupils Canon 85mm comparison (front).jpg
Canon 85mm f/1.8 and f/1.2 showing their large entrance pupils

For scale, note that f/0.5, f/0.7, f/1.0, f/1.4, and f/2.0 are each 1 f-stop apart (2× as fast), as an f-stop corresponds to a factor of the square root of 2, about 1.4. Thus around f/1.0, a change of 0.1 corresponds to about 1/4 of an f-stop (by linear approximation): f/1.0 is about 50% faster than f/1.2, which is about 50% faster than f/1.4.

As of 2017, Canon, Nikon, Pentax and Sony all make an autofocus 50mm f/1.4 lens. These are not unusual lenses and are relatively inexpensive. As of 2023, Canon also makes autofocus 50mm and 85mm f/1.2 lenses, while Nikon makes a manual focus 58mm f/0.95 lens and autofocus 50 and 85mm f/1.2 lenses; see Canon EF 50mm lenses and Canon EF 85mm lenses for details. Pentax makes a 50mm f/1.4 lens and 55mm f/1.4 lens for APS-C cameras; see Pentax lenses. Sony makes several 50mm f/1.4 lenses as well as a 50mm f/1.2.

The maximum exposure time for hand-held photography can be increased with an image stabilisation system. In 2014, Panasonic introduced the fastest lens with in-built stabilisation, the Leica Nocticron 42.5 mm f/1.2, which can even be operated with dual image stabilisation (Dual I.S.), provided that the camera body has an additional stabilising system at the image sensor.

In the mid 1960s, there was something of a fad for fast lenses among the major manufacturers. [4] In 1966, in response to the trend, Carl Zeiss displayed a prop lens christened the Super-Q-Gigantar 40mm f/0.33 at photokina. [4] Made from various parts found around the factory (the lenses came from a darkroom condenser enlarger), the claimed speed and focal lengths were purely nominal and it wasn't usable for photography. [4] [5]

Maximum possible speed

Theoretically, the smallest f-number is 0 (or numerical aperture of 1), corresponding to a lens with an infinite entrance pupil diameter. In practice, that cannot be reached due to mechanical constraints of the camera system (shutter clearance, mount diameter). Even for systems that can be designed without significant constraints on lens size and image plane distance (e.g. microscopy and photolithography systems), the cost of going beyond a numerical aperture of 0.95 (f/0.164) is usually prohibitive.

In SLR camera systems, typical mount diameters are in the range of 44–54 mm, with flange distances around 45 mm. This limits the maximum possible f-number to f/1.0 to f/1.2, with rather strong vignetting towards the edges of the image. Flange distances are significantly smaller for rangefinder and mirrorless cameras (even below 20 mm), theoretically enabling designs down to something like f/0.7 or even faster. The chance of seeing such lenses designed for use with 35mm ("full-frame") cameras, digital or film, in practice will be slim, since their cost and weight are likely not competitive with respect to equivalent imaging solutions employing larger sensors.

List of ultrafast lenses

Some of the fastest camera lenses in production as of 2021 were as follows:

Cosina Voigtlander Super Nokton 29 mm / 0.8 Voigtlaender.Super.Nokton.29F0.8.jpg
Cosina Voigtländer Super Nokton 29 mm / 0.8

The following lenses are no longer in production as of 2021:

Apart from those already mentioned, many very fast lenses exist in C-mount (as used by 16mm film cameras, CCTV, medical & scientific imaging systems), including:

Very fast lenses in D-mount for use in (Super-)8mm film and video (Hi)8 cameras:

Very fast lenses used in X-ray machines:

Related Research Articles

<span class="mw-page-title-main">Aperture</span> Hole or opening through which light travels

In optics, the aperture of an optical system is a hole or an opening that primarily limits light propagated through the system. More specifically, the entrance pupil as the front side image of the aperture and focal length of an optical system determine the cone angle of a bundle of rays that comes to a focus in the image plane.

<span class="mw-page-title-main">Rangefinder camera</span> Camera fitted with a rangefinder

A rangefinder camera is a camera fitted with a rangefinder, typically a split-image rangefinder: a range-finding focusing mechanism allowing the photographer to measure the subject distance and take photographs that are in sharp focus. Most varieties of rangefinder show two images of the same subject, one of which moves when a calibrated wheel is turned; when the two images coincide and fuse into one, the distance can be read off the wheel. Older, non-coupled rangefinder cameras display the focusing distance and require the photographer to transfer the value to the lens focus ring; cameras without built-in rangefinders could have an external rangefinder fitted into the accessory shoe. Earlier cameras of this type had separate viewfinder and rangefinder windows; later the rangefinder was incorporated into the viewfinder. More modern designs have rangefinders coupled to the focusing mechanism so that the lens is focused correctly when the rangefinder images fuse; compare with the focusing screen in non-autofocus SLRs.

<span class="mw-page-title-main">Carl Zeiss AG</span> German optics company

Carl Zeiss AG, branded as ZEISS, is a German manufacturer of optical systems and optoelectronics, founded in Jena, Germany in 1846 by optician Carl Zeiss. Together with Ernst Abbe and Otto Schott he laid the foundation for today's multinational company. The current company emerged from a reunification of Carl Zeiss companies in East and West Germany with a consolidation phase in the 1990s. ZEISS is active in four business segments with approximately equal revenue in almost 50 countries, has 30 production sites and around 25 development sites worldwide.

<span class="mw-page-title-main">Nikkor</span> Brand of lenses produced by Nikon

Nikkor is the brand of lenses produced by Nikon Corporation, including camera lenses for the Nikon F-mount.

Fujinon is a brand of optical lenses made by Fuji Photo Film Co., Ltd, now known as Fujifilm. Fujifilm's Fujinon lenses have been used by professional photographers and broadcast stations as well as cinematography. Fujifilm started manufacture of optical glass in its Odawara Factory in Japan in 1940, which was the start of the Fujinon brand. They were proud of their use of expensive Platinum crucibles to get the purest glass achievable at the time. Fujifilm also pioneered Electron Beam Coating (EBC) which according to Fujifilm, represented a new high in lens precision and performance. The EBC process was significantly different from other coating processes by the number of coating, the thinness of the coating, and the materials used for coating. Fujifilm claimed they were able to have as many as 14 layers of coating and used materials such as zirconium oxide, and cerium fluoride, which could not be used for coating in the conventional coating process. The first lens to offer the Electron Beam Coating was the EBC Fujinon 55mm F3.5 Macro in 1972. Light transmission for the coating was said to be 99.8%. EBC later evolved into Super-EBC and HT-EBC.

<span class="mw-page-title-main">Fisheye lens</span> Wide-angle photographic lens with strong barrel distortion

A fisheye lens is an ultra wide-angle lens that produces strong visual distortion intended to create a wide panoramic or hemispherical image. Fisheye lenses achieve extremely wide angles of view, well beyond any rectilinear lens. Instead of producing images with straight lines of perspective, fisheye lenses use a special mapping, which gives images a characteristic convex non-rectilinear appearance.

<span class="mw-page-title-main">Cosina</span> Japanese optical equipment manufacturer

Cosina Co., Ltd. is a manufacturer of high-end optical glass, optical precision equipment, cameras, video and electronic related equipment, based in Nakano, Nagano Prefecture, Japan.

<span class="mw-page-title-main">Canon FD lens mount</span> Standard lens mount on the Canon

The Canon FD lens mount is a physical standard for connecting a photographic lens to a 35mm single-lens reflex camera body. The standard was developed by Canon of Japan and was introduced in March 1971 with the Canon F-1 camera. It served as the Canon SLR interchangeable lens mounting system until the 1987 introduction of the Canon EOS series cameras, which use the newer EF lens mount. The FD mount lingered through the release of the 1990 Canon T60, the last camera introduced in the FD system, and the end of the Canon New F-1 product cycle in 1992.

<span class="mw-page-title-main">Schneider Kreuznach</span> German company

Jos. Schneider Optische Werke GmbH is a manufacturer of industrial and photographic optics. The company was founded on 18 January 1913 by Joseph Schneider as Optische Anstalt Jos. Schneider & Co. at Bad Kreuznach in Germany. The company changed its name to Jos. Schneider & Co., Optische Werke, Kreuznach in 1922, and to the current Jos. Schneider Optische Werke GmbH in 1998.

<span class="mw-page-title-main">Double-Gauss lens</span>

The double Gauss lens is a compound lens used mostly in camera lenses that reduces optical aberrations over a large focal plane.

<span class="mw-page-title-main">Zeiss Sonnar</span>

The Zeiss Sonnar is a photographic lens originally designed by Dr. Ludwig Bertele in 1929 and patented by Zeiss Ikon. It was notable for its relatively light weight, simple design and fast aperture.

<span class="mw-page-title-main">Leica CL</span> Camera model

The Leica CL is a 35mm compact rangefinder camera with interchangeable lenses in the Leica M-mount. It was developed in collaboration with Minolta who manufactured it. It first appeared in April 1973 and was released in the Japanese market in November 1973 as the Leitz Minolta CL. Both the Leica CL and Leitz Minolta CL were manufactured in a new Minolta factory in Osaka. In 2017, Leica announced a new digital mirrorless camera, again named Leica CL.

Cosina Voigtländer refers to photographic products manufactured by Cosina under the Voigtländer name since 1999. Cosina leases rights to the Voigtländer name from RINGFOTO GmbH & Co. ALFO Marketing KG in Germany. Cosina Voigtländer products have included 35mm film SLR and rangefinder camera bodies, and lenses for the M39 lens mount, M42 lens mount, Leica M mount, and other lens mounts.

The Jupiter series of lenses are Russian camera lenses made by various manufacturers in the former Soviet Union. They were made to fit many camera types of the time, from pre-WWII rangefinders to almost modern SLRs. They are copied from Zeiss pre-WWII designs with incremental improvements, such as coatings, introduced during production. The majority of them are based on Zeiss Sonnar optical scheme, but that's not a rule.

<span class="mw-page-title-main">Zeiss Biogon</span> Series of photographic camera lenses

Biogon is the brand name of Carl Zeiss for a series of photographic camera lenses, first introduced in 1934. Biogons are typically wide-angle lenses.

<span class="mw-page-title-main">Topogon</span>

Topogon is a wide field, symmetrical photographic lens patented by Robert Richter in 1933 for Carl Zeiss AG. As there are four meniscus elements in four groups, deployed symmetrically around the central aperture, it is considered a double Gauss lens variant.

<span class="mw-page-title-main">Fujifilm X-mount</span> Type of interchangeable lens mount

The Fujifilm X-mount is a lens mount for Fujifilm interchangeable lens mirrorless cameras in its X-series, designed for 23.6mm x 15.6mm APS-C sensors.

<span class="mw-page-title-main">History of photographic lens design</span>

The invention of the camera in the early 19th century led to an array of lens designs intended for photography. The problems of photographic lens design, creating a lens for a task that would cover a large, flat image plane, were well known even before the invention of photography due to the development of lenses to work with the focal plane of the camera obscura.

References

  1. Waldren, Margaret (and others) Advanced Digital Photography 2004 Media Publishing
  2. Long, Ben Complete Digital Photography 2004 Charles River Media
  3. "F0.74 - new Metabones Speed Boosters break boundaries - EOSHD". EOSHD. 2 December 2013. Retrieved 2015-11-19.
  4. 1 2 3 Maiello, Agostino (January 2000). "L'OBIETTIVO PIU' LUMINOSO DEL MONDO". Nadir.it (in Italian). Nadir Magazine. Retrieved 28 September 2013.
  5. Zhang, Michael (August 6, 2013). "Carl Zeiss Super-Q-Gigantar 40mm f/0.33: The Fastest Lens Ever Made?". Petapixel. Retrieved 28 September 2013.
  6. "Cosina Voigtänder - Nokton 25mm F0.95". Cosina Voigtländer. 2010-08-26. Archived from the original on 2013-12-12. Retrieved 2013-12-03.
  7. "29 mm / 1:0,8 Super Nokton asphärisch | Voigtländer". www.voigtlaender.de.
  8. "MFT- Mount | Voigtländer". www.voigtlaender.de.
  9. "Leica offers World's fastest Aspherical lens". Leica Camera. 2008-09-15. Retrieved 2009-02-14.
  10. photonstophotos.net. 8 May 2022 https://photonstophotos.net/GeneralTopics/Lenses/OpticalBench/OpticalBench.htm#Data/CN111965793_Example01P.txt,figureOpacity=0.25,AxisO,OffAxis.{{cite web}}: Missing or empty |title= (help)
  11. "USAF Lens Datasheets - Type 1 Aerial Reconnaissance". archive.org. Retrieved 4 October 2013.
  12. "Signal Corps Engineering Laboratories 33mm f/0.6 Lens - Nov 19, 2011 | Fuller's LLC in PA".
  13. "Fujinon-IDEAX 125mm f0.67 (f0.85?)". forum.mflenses.com.
  14. Two Special Lenses for "Barry Lyndon", by Ed DiGiulio (President, Cinema Products Corp.), American Cinematographer
  15. Volosov, David (1978). Fotograficheskaya optika.
  16. "TV-Nikkor 35mm F0.9 Big First Super Light". Archived from the original on June 30, 2013. Retrieved 2016-05-14.
  17. Lossau, Jürgen (2003). The Complete Catalogue Of Movie Cameras, Hamburg/Germany, atoll medien, p. 59, ISBN   3-9807235-3-4
  18. Brandenberger, Arthur (1961). "The Use of Baker-Nunn Cameras for Tracking of Artificial Earth Satellites" (PDF). American Society for Photogrammetry and Remote Sensing (ASPRS). 28th Annual Meeting: 9.
  19. "Science, Kern-Paillard advertisement". 165.{{cite journal}}: Cite journal requires |journal= (help)
  20. "Carl Meyer Videostigmat f1.0 1.5" (38mm)". forum.mflenses.com.
  21. "Rodenstock XR-heligon 68mm F1.0 M42 mount".