Lens adapters Exakta to Sony E-mount and Minolta MD to Sony E-mount

photography Photography is the art, application, and practice of creating durable images by recording light, either electronically by means of an image sensor, or chemically by means of a light-sensitive material such as photographic film. It is employe ...

and

videography Videography is the process of capturing moving images on electronic media (e.g., videotape, direct to disk recording, or solid state storage) and even streaming media. The term includes methods of video production and post-production. It used ...

, a lens adapter is a device that enables the use of camera and lens combinations from otherwise incompatible systems. The most simple lens adapter designs, passive lens adapters provide a secure physical connection between the camera and the lens. Some passive adapters may include a mechanism for manual

iris Iris most often refers to: *Iris (anatomy), part of the eye *Iris (mythology), a Greek goddess * ''Iris'' (plant), a genus of flowering plants * Iris (color), an ambiguous color term Iris or IRIS may also refer to: Arts and media Fictional ent ...

control. So called, active lens adapters will include electronic connections, enabling communication between the lens and the camera. Some lens adapters include a special optical element called a telecompressor, focal reducer, or more recently a "speed booster", a

genericised trademark A generic trademark, also known as a genericized trademark or proprietary eponym, is a trademark or brand name that, because of its popularity or significance, has become the generic term for, or synonymous with, a general class of products or ...

that refers to the Metabones Speed Booster line of lens adapters. This type of adapter is designed to reduce focal length, increase lens speed, and in some instances improve MTF performance. Another innovator in the field is KIPON, a German/Chinese co-operation between Kipon and IB/E Optics. Another branch of lens adapters include an ND-filter to simplify changing lenses, which HolyManta introduced in 2013. The depth-of-field adapter (also called a DOF adapter or 35 mm adapter) is a largely obsolete device that uses a

ground glass Ground glass is glass whose surface has been ground to produce a flat but rough (matte) finish, in which the glass is in small sharp fragments. Ground glass surfaces have many applications, ranging from ornamentation on windows and table glassw ...

focusing screen to enable the use of interchangeable lenses on a fixed lens

camcorder A camcorder is a self-contained portable electronic device with video and recording as its primary function. It is typically equipped with an articulating screen mounted on the left side, a belt to facilitate holding on the right side, hot-swa ...

.Bloom, Philip
"35mm Adapters"
There are also lens adapters made for other optical systems, including

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s and

telescope A telescope is a device used to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation. Originally meaning only an optical instrument using lenses, curved mirrors, or a combination of both to observ ...

Basic design

Most lens adapters feature a male fitting and a female fitting. The male fitting attaches to the camera, and the female fitting attaches to the lens. There is also an opening in the center to allow the light to pass through. Lens adapters can be shorter or longer, based on the respective flange focal distance of the lens and camera being adapted. Flange focal distance is the key specification in determining whether or not a particular type of lens can be adapted to any given camera. Generally speaking, cameras with a shorter flange focal distance can be adapted to a greater diversity of lenses. This is because there must be enough room to fit an adapter between the lens and the camera. It is possible to physically mount a lens with a short flange focal distance on a camera with a long flange focal distance, but this will make it impossible to achieve

infinity focus In optics and photography, infinity focus is the state where a lens or other optical system forms an image of an object an infinite distance away. This corresponds to the point of focus for parallel rays. The image is formed at the focal point ...

. The effect will be similar to that of an

extension tube An extension tube, sometimes also called a closeup tube or an extension ring, is used with interchangeable lenses to increase magnification. This is most often used in macro photography. Construction The tube contains no optical elements; it ...

, because the lens will be mounted further from the image plane than intended. Some lens adapters utilize an optical element to compensate for this, effectively acting as a

teleconverter A teleconverter (sometimes called tele extender) is a secondary lens mounted between a camera and a photographic lens which enlarges the central part of an image obtained by the lens. For example, a 2× teleconverter for a 35 mm camera enl ...

. This introduces the typical side effects of a teleconverter, namely decreasing the amount of light that reaches the sensor, and adding a

crop factor In digital photography, the crop factor, format factor, or focal length multiplier of an image sensor format is the ratio of the dimensions of a camera's imaging area compared to a reference format; most often, this term is applied to digital ca ...

to the lens. Additionally, there are several secondary factors to consider. Lenses designed for a smaller image sensor may not be adaptable to camera bodies with larger sensors as the

image circle The image circle is the cross section of the cone of light transmitted by a lens or series of lenses onto the image plane. When this light strikes a perpendicular target such as photographic film or a digital camera sensor, it forms a circle of ...

may not be large enough to cover the entire sensor, and will therefore exhibit

vignetting In photography and optics, vignetting is a reduction of an image's brightness or saturation toward the periphery compared to the image center. The word '' vignette'', from the same root as ''vine'', originally referred to a decorative bord ...

. The age of the camera body may limit the availability of adapters; as camera bodies typically reach obsolescence before lenses. Finally, some adapters may include electronic or mechanical provisions in order to control the lens aperture and

autofocus An autofocus (or AF) optical system uses a sensor, a control system and a motor to focus on an automatically or manually selected point or area. An electronic rangefinder has a display instead of the motor; the adjustment of the optical system ...

, to record the correct

Exif Exchangeable image file format (officially Exif, according to JEIDA/JEITA/CIPA specifications) is a standard that specifies formats for images, sound, and ancillary tags used by digital cameras (including smartphones), scanners and other syste ...

data, or to report focus confirmation. The following table shows commonly available adapters that don't require an optical element. †Image may exhibit vignetting due to sensor size. ‡Theoretically possible, but may be difficult to find. ∗Although the camera's flange distance is shorter than the lens', there is not enough distance between the flange and the lens to integrate the bayonet.

References

{{reflist Photography equipment

Basic design

See also

References