Lens mount

A lens mount is an interface – mechanical and often also electrical – between a photographic camera body and a lens. It is a feature of camera systems where the body allows interchangeable lenses, most usually the rangefinder camera, single lens reflex type, single lens mirrorless type or any movie camera of 16 mm or higher gauge. Lens mounts are also used to connect optical components in instrumentation that may not involve a camera, such as the modular components used in optical laboratory prototyping which join via C-mount or T-mount elements.

Mount types

A lens mount may be a screw-threaded type, a bayonet-type, or a breech-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 mounts generally have a number of tabs 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 by rotating it in the opposite direction.
Lens mounts of competing manufacturers 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 allege that these incompatibilities are due to the desire of manufacturers to "lock in" consumers to their brand.
In movie cameras, the two most popular mounts in current usage on professional digital cinematography cameras are Arri's PL-mount and Panavision's PV-mount. The PL-Mount is used both on Arri and RED digital cinematography cameras, which are the most used cameras for 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.

List of lens mounts

Mount name	Flange focal distance	Frame size	Throat or thread diameter	Mount thread pitch	Mount type	Primary use	Camera lines
Kinor 16SP	52 mm	16 mm	43 mm		Breech lock	Cinematography	Kinor 16SP, Krasnogorsk-1, -2, -3 16mm movie cameras
Kinor 16SX	52 mm	16 mm	43 mm		Breech lock	Cinematography	Kinor 16SX-1M,-2M 16mm movie camera
OST/OCT-19	68 mm	35 mm	61 mm		Breech lock	Cinematography	Konvas-2M, Kinor-35H 35mm movie cameras
Kiev-16U	31 mm	16 mm	32 mm	mm	Screw	Cinematography	Kiev-16U/UE 16mm movie cameras
Kiev-16C	mm	16 mm	27 mm	mm	Screw		Kiev-1C 16mm movie camera
Canon SV	mm				Bayonet	Photography	Canon RC-701 & 760
Argus C3	mm	35 mm	34 mm	20 TPI	Screw	Photography	Argus C3
Canon EX	20 mm	1/2"			Bayonet	Photography
Canon FL	42 mm	35 mm	48 mm		Breech lock	Photography
Canon FD	42 mm	35 mm	48 mm		Breech lock	Photography	Canon F series, A series, and T series SLRs
Canon FDn	42 mm	35 mm	48 mm		Bayonet	Photography	completely interchangeable with earlier FD lenses
Canon EF	mm	35 mm	54 mm		Bayonet	Photography	Canon EOS 35mm film SLR, Full Frame & APS-H DSLR
Canon EF-S	mm	APS-C	54 mm		Bayonet	Photography	Canon EOS APS-C DSLR
Canon EF-M	18 mm	APS-C	47 mm		Bayonet	Photography	Canon EOS M series Mirrorless APS-C Cameras
Canon RF	20 mm	35 mm and APS-C	54 mm		Bayonet	Photography	Canon EOS R series full-frame and APS-C mirrorless cameras; lenses designated as RF-S are optimized for APS-C sensors, but will mount on full-frame bodies
Nikon S	mm	35 mm	34 mm		Bayonet	Photography	Nikon Rangefinder
Nikon F	mm	35 mm	44 mm		Bayonet	Photography	Nikon F 35mm film SLR, Full Frame & APS-C DSLR
Nikon 1	17 mm	13.2 x 8.8mm	40 mm		Bayonet	Photography	Nikon 1 series
Nikon Z	16 mm	35 mm	55 mm		Bayonet	Photography	Nikon Z - Mirrorless Full Frame, APS-C, & video
Sony Mavica	57 mm				Bayonet	Photography
Sony E-mount\|Sony E \| FE	18 mm	35 mm and APS-C	mm		Bayonet	Photography	Sony NEX\|Sony E/FE Mount Alpha Mirrorless Full Frame / APS-C\| Sony NEX Mirrorless APS-C
Minolta SR	mm	35 mm	mm		Bayonet	Photography	Minolta SR/MC/MD
Minolta V	mm	APS-H	mm		Bayonet	Photography	Minolta Vectis
Minolta A	mm	35 mm and APS-C	mm		Bayonet	Photography	Minolta DSLR AF/Alpha/Dynax/Maxxum Sony DSLR Alpha A Mount
Pentax Auto 110	27 mm	110 film	mm		Bayonet	Photography	Pentax Auto 110 and Auto 110 Super
Pentax Q	mm	1/2.3", 1/1.7"	31 mm		Bayonet	Photography
Pentax K	mm	35 mm and APS-C	44 mm		Bayonet	Photography	Used also by Ricoh, Chinon, Agfa, Vivitar and KMZ Zenit cameras
Leitz Visoflex I	mm	35 mm	M39	26 TPI	Screw	Photography
Leitz Visoflex II/III	mm	35 mm	44 mm		Bayonet	Photography
Leica M	mm	35 mm	44 mm		Bayonet	Photography	Leica M series Leica CL Minolta CLE
Leica R	mm	35 mm	49 mm		Bayonet	Photography
Leica L	20 mm	35 mm and APS-C	mm		Bayonet	Photography	L-Mount Alliance
Contax RF	mm	35 mm	44 mm		Double bayonet	Photography	Contax I, II, III, IIa, IIIa Kiev rangefinders
Contax G	mm	35 mm	44 mm		Breech lock	Photography
Contax N	48 mm	35 mm	55 mm		Bayonet	Photography
Contax/Yashica	mm	35 mm	48 mm		Bayonet	Photography	Yashica/Contax
Yashica MA	~45.8 mm	35 mm			Bayonet	Photography	Kyocera Yashica 230 AF etc.
Fujica X	mm	35 mm	49 mm		Bayonet	Photography	Fujica-X
Fujifilm X	mm	APS-C	44 mm		Bayonet	Photography	Fujifilm X series mirrorless
Olympus Pen F	mm	35 mm half-frame			Bayonet	Photography
Olympus OM	46 mm	35 mm	46 mm		Bayonet	Photography
Four Thirds	mm	17.3 mm × 12.98 mm	~44 mm		Bayonet	Photography	Olympus E Panasonic Lumix DMC-L Leica Digilux
Micro Four Thirds	mm	17.3 mm × 12.98 mm	~38 mm		Bayonet	Photography	Olympus Pen & OM-D series Panasonic G, GF, GX & GH Series Blackmagic Design Cinema Camera
KM	28 mm	35 mm	44 mm		Bayonet	Photography	Konica Hexar RF
Konica F	mm	35 mm	40 mm		Bayonet	Photography	Konica F
Konica AR	mm	35 mm	47 mm		Bayonet	Photography	Konica Autoreflex
Samsung NX mini	mm	1"	38 mm		Bayonet	photography
Samsung NX	mm	APS-C	42 mm		Bayonet	Photography
Samsung Kenox	mm	35 mm			Bayonet	Photography	Manual focus only; there is only one compatible camera - Samsung Kenox GX-1/Samsung SR4000.
DJI DL	mm	35 mm and APS-C	58 mm		Bayonet	Photography, Cinematography	For aerial drone and gimbal use; DJI Zenmuse X7, X9 and DJI Ronin 4D X9 cameras.
Icarex BM	mm	35 mm			Breech lock	Photography	Icarex 35S
D	mm	8 mm	mm	32 TPI	Screw	Cinematography
CS	6 mm	1/3", 1/2"	mm	32 TPI	Screw	Cinematography / Industrial
C	mm	1/2", 16 mm, 2/3", 1"	mm	32 TPI	Screw	Cinematography / Industrial / Machine Vision
S	N/A. Screw mount must be adjusted manually for back focus. Back focal distance from <1mm to 12mm.	1/6" to 1"	12 mm	0.5 mm pitch	Screw	CCTV, PCB	Edmund Optics μ-Video
Bolex Bajonet	mm	16 mm			Breech lock	Cinematography	effective focal distance mm due to beam splitter behind mount flange
1/3" bayonet mount	25 mm	1/3"			Bayonet	Video	JVC professional video cameras
M39	mm	35 mm	M39	26 TPI	Screw	Photography	Leica M39 screw mount
Narciss	mm	16 mm	M24	1 mm	Screw	Photography
1/2" bayonet mount	mm	1/2"			Bayonet	Video	Non-Sony professional video cameras
Alpa	mm	35 mm	42 mm		Bayonet	Photography
Sony 1/2" Video	38 mm	1/2"			Bayonet	Video	Sony professional video cameras
Aaton universal	40 mm	16 mm	50 mm		Breech lock	Cinematography
Miranda bayonet/M44	mm	35 mm and APS-C			Bayonet	Photography	Miranda Camera Company
Petriflex	mm	35 mm			Breech lock	Photography
Sigma SA	mm	35 mm	44 mm		Bayonet	Photography	Sigma SA
Paxette	44 mm	35 mm	M39	1 mm	Screw	Photography
Praktiflex	44 mm	35 mm	M40	1 mm	Screw	Photography
Praktica	mm	35 mm	42 mm		Bayonet	Photography
Exakta	mm	35 mm	46 mm		Bayonet	Photography	Exakta, Topcon Super
Zenit M39	mm	35 mm	M39	1 mm	Screw	Photography
M37	mm	35 mm	37 mm	1 mm	Screw	Photography	Asahiflex
M42	mm	35 mm	42 mm	1 mm	Screw	Photography	Praktica, Pentax, Zenit
B4-mount	48 mm	2/3"			Bayonet	Video	Professional and broadcast video cameras
Praktina	50 mm	35 mm	46 mm		Breech lock	Photography
T-Thread	mm	35 mm	M37	0.75mm	Screw	Photography	Tamron
Adapt-A-Matic	mm	35 mm	54 mm		Bayonet	Photography	Tamron
Adaptall & Adaptall-2	mm	35 mm	54 mm		Bayonet	Photography	Tamron
Arri standard	52 mm	35 mm and 16 mm	64 mm		Tab lock	Cinematography
Arri bayonet	52 mm	35 mm and 16 mm	64 mm		Bayonet	Cinematography
Arri PL	52 mm	35 mm and 16 mm	54 mm		Breech lock	Cinematography
Arri LPL	44 mm	Arri LF	62 mm		Breech lock	Cinematography
Arri Maxi PL	52 mm	70 mm	64 mm			Cinematography
T	55 mm	35 mm	42 mm	0.75 mm	Screw	Photography	Tamron
YS Auto T-Thread	55 mm	35 mm	42 mm	0.75 mm	Screw	Photography	Sigma Corporation
T-thread	55 mm	35 mm	47 mm	0.75 mm	Screw	Photography	Tokina
H-Mount	55 mm	35 mm	47 mm	0.75 mm	Screw	Photography	Hanimex
Panavision PV	mm	35 mm	mm		Breech lock	Cinematography
B3-mount	58 mm	2/3"			Reverse bayonet	Video	Ikegami
Mitchell BNCR	mm	35 mm	68 mm		Breech lock	Cinematography
Zeiss Panflex 5522/23 for Contax RF	mm	35 mm			Double bayonet	Photography
Kowa Six/Super 66	79 mm	6×6			Breech lock	Photography
Hasselblad	mm	6×6	69 mm		Bayonet	Photography
Hasselblad Xpan	mm	35 mm panoramic	46 mm		Bayonet	Photography
Bronica ETR	69 mm	6×4.5			Bayonet	Photography
Bronica RF	mm	6×4.5			Bayonet	Photography
Bronica SQA	mm	6×6	57 mm		Bayonet	Photography
Bronica GS1	85 mm	6×7	mm		Bayonet	Photography
Mamiya 645	mm	6×4.5	62 mm		Bayonet	Photography
Mamiya 6	mm	6×6			Bayonet	Photography
Mamiya 7/7II	59 mm	6×7	49 mm		Bayonet	Photography
Mamiya RZ67	105 mm	6×7	60 mm		Bayonet	Photography
Mamiya RB67	112 mm	6×7	60 mm		Bayonet	Photography
Mamiya ZE	mm	35 mm			Bayonet	Photography
Mamiya/Sekor E	mm	35 mm	49 mm		Bayonet	Photography
Pentax 645	mm	6×4.5	mm		Bayonet	Photography
Pentax 6x7	mm	6×7	72 mm		Bayonet	Photography
Pentacon Six	mm	6×6	60 mm		Breech lock	Photography
Fujifilm G	mm	43.8x32.9 mm	65 mm		Bayonet	Photography	Fujifilm GFX series
Rolleiflex SL66	mm	6×6			Bayonet	Photography
Rolleiflex SL35	mm	35 mm	46 mm		Bayonet	Photography
RMS thread, society thread	150/180 mm		0.8", Whitworth	36 tpi	Screw	Microscope	older microscopes
Leica Nikon Biological	Unknown		M25	0.75 mm	Screw	Microscope
BD Mount	Unknown		M26	0.7 mm	Screw	Microscope	Mitutoyo Olympus BD Nikon BD
Zeiss	Unknown		M27	0.75 mm	Screw	Microscope
TFL	mm	28 mm	M35	0.75 mm	Screw	Machine Vision
TFL II	mm	35 mm	M48	0.75 mm	Screw	Machine Vision
Pentax Auto 110	27 mm	110 Film	20.6 mm		Bayonet	Photography	Auto 110

For small camera modules, used in e.g. CCTV systems and machine vision, a range of metric thread mounts exists. The smallest ones can be found also in e.g. cellphones and endoscopes. The most common by far is the M12x0.5, followed by M8x0.5 and M10x0.5.

M4.2x0.2
M4.6x0.25
M5x0.35
M5.5x0.35
M6x0.35
M6.4x0.25
M7x0.35
M8x0.35
M8x0.5
M9x0.5
M10x0.5
M12x0.5
M22x0.5