Matches in DBpedia 2016-04 for { <http://dbpedia.org/resource/Lens_speed> ?p ?o }
- Lens_speed abstract "Lens speed refers to the maximum aperture diameter, or minimum f-number, of a photographic lens. A lens with a larger maximum aperture (that is, a smaller minimum f-number) is called a \"fast lens\" because it delivers more light intensity (illuminance) to the focal plane, achieving the same exposure with a faster shutter speed. It also needs to reduce interference from extraneous (light) noise i.e. lower the noise floor. A smaller maximum aperture (larger minimum f-number) is \"slow\" because it delivers less light intensity i.e. has a higher noise floor and requires a slower shutter speed.A lens may be referred to as \"fast\" or \"slow\" depending on its maximum aperture compared to other lenses of similar focal length designed for a similar film format. Lens speed given by the minimum f-number, or alternatively maximum aperture diameter or maximum numerical aperture, is a useful quantitative way to compare similar lenses.Lens speed is important in taking pictures in dim light, or with long telephoto lenses. For controlling depth of field, especially in portrait photography, lens speed is a key variable in combination with other variables such as focal length and camera format size.Lenses may also be referred to as being \"faster\" or \"slower\" than one another using this same method. A lens with a maximum aperture of f/3.5 is faster than one with an aperture of f/5.6, though neither is especially fast. A lens with an aperture of f/1.8 is slower than a lens with an aperture of f/1.2, though both are fast lenses.The range of lenses 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 Encyclopaedia 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.\"With 35mm cameras, the fastest lenses are typically in the \"normal lens\" range near 50mm. Longer telephoto designs and wide-angle retrofocus designs tend to be slower. Attaining maximum lens speed requires engineering tradeoffs, and as such, \"prime\" (fixed focal length) lenses are generally faster than zoom lenses, and modern manual-focus lenses are generally faster than their autofocus counterparts.The fastest lenses in general production are f/1.2 or f/1.4, with more at f/1.8 and f/2.0, and many at f/2.8 or slower; f/1.0 is unusual, though sees some use, e.g. the discontinued Canon 50mm f/1.0, and highly unusual older examples of f/0.6, f/0.7, f/0.8, f/0.9 etc. exist, e.g. the Zeiss 50mm f/0.7 NASA Kubrick lenses adapted to old film cameras and modern DV cameras.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. However, there are several high-quality fast lenses available that are relatively inexpensive, particularly in normal lens focal lengths. 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, just as the Nikkor-S(C) or Nikkor AI-S 50mm f/1.4, were historically produced abundantly, and are thus sold relatively inexpensively on the used lens market.".
- Lens_speed thumbnail Lensspeed.jpg?width=300.
- Lens_speed wikiPageExternalLink fast.html.
- Lens_speed wikiPageID "7296395".
- Lens_speed wikiPageLength "19565".
- Lens_speed wikiPageOutDegree "135".
- Lens_speed wikiPageRevisionID "699239594".
- Lens_speed wikiPageWikiLink APS-C.
- Lens_speed wikiPageWikiLink Aerojet_Delft.
- Lens_speed wikiPageWikiLink American_Optical.
- Lens_speed wikiPageWikiLink Angénieux_retrofocus.
- Lens_speed wikiPageWikiLink Aperture.
- Lens_speed wikiPageWikiLink Aspheric_lens.
- Lens_speed wikiPageWikiLink Astro_Berlin.
- Lens_speed wikiPageWikiLink Barry_Lyndon.
- Lens_speed wikiPageWikiLink C_mount.
- Lens_speed wikiPageWikiLink Camera_lens.
- Lens_speed wikiPageWikiLink Canon_EF_50mm_lens.
- Lens_speed wikiPageWikiLink Canon_EF_85mm_lens.
- Lens_speed wikiPageWikiLink Canon_EF_lens_mount.
- Lens_speed wikiPageWikiLink Canon_Inc..
- Lens_speed wikiPageWikiLink Cardinal_point_(optics).
- Lens_speed wikiPageWikiLink Carl_Zeiss.
- Lens_speed wikiPageWikiLink Carl_Zeiss_AG.
- Lens_speed wikiPageWikiLink 0.7.
- Lens_speed wikiPageWikiLink Category:Optics.
- Lens_speed wikiPageWikiLink Category:Science_of_photography.
- Lens_speed wikiPageWikiLink Closed-circuit_television.
- Lens_speed wikiPageWikiLink Cosina_Voigtländer.
- Lens_speed wikiPageWikiLink Depth_of_field.
- Lens_speed wikiPageWikiLink Encyclopædia_Britannica_Eleventh_Edition.
- Lens_speed wikiPageWikiLink Enlarger.
- Lens_speed wikiPageWikiLink F-number.
- Lens_speed wikiPageWikiLink Fabrication_and_testing_of_optical_components.
- Lens_speed wikiPageWikiLink Farrand_(camera).
- Lens_speed wikiPageWikiLink File:Lensspeed.jpg.
- Lens_speed wikiPageWikiLink Film_format.
- Lens_speed wikiPageWikiLink Focal_length.
- Lens_speed wikiPageWikiLink Fujifilm.
- Lens_speed wikiPageWikiLink Fujinon.
- Lens_speed wikiPageWikiLink Illuminance.
- Lens_speed wikiPageWikiLink JML_Optical.
- Lens_speed wikiPageWikiLink Kern_Switar.
- Lens_speed wikiPageWikiLink Kinoptik.
- Lens_speed wikiPageWikiLink Kollmorgen.
- Lens_speed wikiPageWikiLink Kowa_Co..
- Lens_speed wikiPageWikiLink LOMO.
- Lens_speed wikiPageWikiLink Leica_Camera.
- Lens_speed wikiPageWikiLink Lens_mount.
- Lens_speed wikiPageWikiLink Lenzar_Optics.
- Lens_speed wikiPageWikiLink Linear_approximation.
- Lens_speed wikiPageWikiLink List_of_IMAX_films.
- Lens_speed wikiPageWikiLink Micro_Four_Thirds_system.
- Lens_speed wikiPageWikiLink 1.4.
- Lens_speed wikiPageWikiLink Mirrorless_interchangeable-lens_camera.
- Lens_speed wikiPageWikiLink NASA.
- Lens_speed wikiPageWikiLink Nikkor.
- Lens_speed wikiPageWikiLink Nikon.
- Lens_speed wikiPageWikiLink 1.8D.
- Lens_speed wikiPageWikiLink Noise_floor.
- Lens_speed wikiPageWikiLink Noktor.
- Lens_speed wikiPageWikiLink Normal_lens.
- Lens_speed wikiPageWikiLink Numerical_aperture.
- Lens_speed wikiPageWikiLink Optical_coating.
- Lens_speed wikiPageWikiLink Optical_lens_design.
- Lens_speed wikiPageWikiLink Pacific_Optical.
- Lens_speed wikiPageWikiLink Panavision.
- Lens_speed wikiPageWikiLink Pentax_(lens).
- Lens_speed wikiPageWikiLink PerkinElmer.
- Lens_speed wikiPageWikiLink Photokina.
- Lens_speed wikiPageWikiLink Prime_lens.
- Lens_speed wikiPageWikiLink Rangefinder_camera.
- Lens_speed wikiPageWikiLink Rayxar.
- Lens_speed wikiPageWikiLink Refractive_index.
- Lens_speed wikiPageWikiLink Rodenstock_GmbH.
- Lens_speed wikiPageWikiLink Schneider_Kreuznach.
- Lens_speed wikiPageWikiLink Shutter_speed.
- Lens_speed wikiPageWikiLink Signal_Corps_Laboratories.
- Lens_speed wikiPageWikiLink Single-lens_reflex_camera.
- Lens_speed wikiPageWikiLink Soligor.
- Lens_speed wikiPageWikiLink South_Pole.
- Lens_speed wikiPageWikiLink Spherical_aberration.
- Lens_speed wikiPageWikiLink Square_root_of_2.
- Lens_speed wikiPageWikiLink Stanley_Kubrick.
- Lens_speed wikiPageWikiLink Super_8_film.
- Lens_speed wikiPageWikiLink Tachon_Astro-Berlin.
- Lens_speed wikiPageWikiLink Telephoto_lens.
- Lens_speed wikiPageWikiLink Topcon.
- Lens_speed wikiPageWikiLink Vavilov_State_Optical_Institute.
- Lens_speed wikiPageWikiLink Wild_Heerbrugg.
- Lens_speed wikiPageWikiLink Wray_(lenses).
- Lens_speed wikiPageWikiLink Zoom_lens.
- Lens_speed wikiPageWikiLink Рекорд-4.
- Lens_speed wikiPageWikiLink File:Canon_85mm_comparison_(front).jpg.
- Lens_speed wikiPageWikiLinkText ""fast" lens".
- Lens_speed wikiPageWikiLinkText "Lens Speed".
- Lens_speed wikiPageWikiLinkText "Lens speed".
- Lens_speed wikiPageWikiLinkText "fast aperture".
- Lens_speed wikiPageWikiLinkText "fast lens".
- Lens_speed wikiPageWikiLinkText "fast lenses".