#Big aperture lens manual#

As of 2022, Canon also makes autofocus 50mm and 85mm f/1.2 lenses, while Nikon makes a manual focus 58mm f/0.95 lens and an autofocus 85mm f/1.4 see Canon EF 50mm lenses and Canon EF 85mm lenses for details. These are not unusual lenses and are relatively inexpensive. 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.Īs of 2017, Canon, Nikon, Pentax and Sony all make an autofocus 50mm f/1.4 lens. 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.Ĭanon 85mm f/1.8 and f/1.2 showing their large entrance pupilsįor 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. For example, the 1911 Encyclopædia Britannica states that '. 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. 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. For example, the Metabones 0.58x BMPCC speed booster may be combined with a f/1.2 lens to produce f/0.74. Thus, faster telephoto and wide-angle retrofocus designs tend to be much more expensive.Ī 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. At wide apertures, spherical aberration becomes more significant and must be corrected. This is because lenses with larger maximum apertures require greater care with regard to design, precision of manufacture, special coatings and quality of glass.

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.Įspecially outside of the 'normal' focal length, lens speed also tends to correlate with the price and/or quality of the lens. 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. 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. 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.Īttaining maximum lens speed requires engineering tradeoffs, and as such, ' prime' (fixed focal length) lenses are generally faster than zoom lenses.

#Big aperture lens full#

format covered, such as APS, full frame, medium format), and in the case of zoom lenses, zoom factor. What is considered fast largely depends on focal length, image diameter (i.e. 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. Conversely, a smaller maximum aperture (larger minimum f-number) is 'slow' because it delivers less light intensity and requires a slower (longer) shutter speed.Ī 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, as well as for sports photography and photojournalism. 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. Lens speed refers to the maximum aperture diameter, or minimum f-number, of a photographic lens. 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.