Editing Lens mount (section)

== Mount types ==
A lens mount may be a screw-threaded type, a [[Bayonet#Linguistic impact|bayonet]]-type, or a [[breech-lock]] (friction lock) type. Modern still camera lens mounts are of the bayonet type, because the bayonet mechanism precisely aligns mechanical and electrical features between lens and body.  Screw-threaded mounts are fragile and do not align the lens in a reliable rotational position, yet types such as the C-mount interface are still widely in use for other applications like video cameras and optical instrumentation.

[[Bayonet mount]]s generally have a number of tabs (often three) around the base of the lens, which fit into appropriately sized recesses in the lens mounting plate on the front of the camera. The tabs are often "keyed" in some way to ensure that the lens is inserted in only one orientation, often by making one tab a different size. Once inserted the lens is fastened by turning it a small amount. It is then locked in place by a spring-loaded pin, which can be operated to remove the lens.

Lens mounts of competing manufacturers (Sony, Nikon, Canon, Contax/Yashica, Pentax, etc.) are almost always incompatible.  In addition to the mechanical and electrical interface variations, the [[flange focal distance]] from the lens mount to the film or sensor can also be different.  Many{{Who|date=May 2016}} allege that these incompatibilities are due to the desire of manufacturers to "[[vendor lock-in|lock in]]" consumers to their brand.{{Citation needed|date = May 2016}}

In movie cameras, the two most popular mounts in current usage on professional [[digital cinematography]] cameras are [[Arri]]'s [[Arri PL|PL-mount]] and [[Panavision]]'s [[PV mount|PV-mount]]. The PL-Mount is used both on Arri and [[Red Digital Cinema Camera Company|RED]] digital cinematography cameras, which {{As of|2012|lc = y}} are the most used cameras for [[List of films shot in digital|films shot in digital]]. The Panavision mounts are exclusively used with Panavision lenses, and thus are only available on Panaflex cameras or third-party cameras "Panavised" by a Panavision rental house, whereas the PL-mount style is favored with most other cameras and [[cine lens]] manufacturers. Both of these mounts are held in place with locating pins and friction locking rings. Other mounts which are now largely historical or a minority in relation to current practices are listed below.