Alphabetical List of Camera Mounts

This is basically a reformatting of the wonderful list published by William-Jan Markerink. See also this list. There is also a wonderful page with photographs of different mounts.

I have made the following changes:

The same list is available sorted in order of register distance here.

Some Issues with Adapting Lenses

At first glance, adapting a lens to fit a camera seems quite straightforward, if the two registers relate in the correct way. That is, the new camera has a register distance less than that of the camera originally intended for the lens. Unfortunately, several things can get in the way.

First, lens mounts for movie cameras are generally designed so the lens extends quite far into the camera behind the flange surface. I suspect this is done to get a much stiffer, stronger connection between lens and camera. Still SLR lenses don't extend very far into the camera, because space is needed for the mirror to move.

Second, the diameter of the mount matters: your lens might be too fat to attach at the correct register.

Third, some lens mounts depend on the camera body to set the aperture; the Contarex and Icarex mounts fall in this category, as does the obscure mount of the Kiev 10 and 15. Any adapter ill need to provide some mechanism to control aperture.

Finally, some cameras (e.g. Zeiss Contaflex) don't let you remove the entire lens, but offer interchangeable front elements to provide different focal lengths. Needless to say, adapting such half-lenses to another camera won't work. I believe the interchangeable elements for the Contaflex were all named "Pro-Tessar".

Camera System Mount type Register Diameter Comments
4/3 System digital bayonet 38.58 44 Designed by Olympus, this mount is apparently mechanically identical to the Olympus OM mount, but with a smaller register. An OM-to-4/3 adapter is just an extension tube.

Aaton PL-40 breech lock 40 50.00mm (1972) User manual confirms. All PL=Positive Lock mounts are inherited from the Mitchell BNCR mount.
Adaptall bayonet(?) 50.7   Also Adapt-A-Matic, Adaptall 2
Alpa bayonet 37.8 42  
Altix breech lock 42.5 34 Used on postwar 35mm cameras of VEB Altissa-Camera-Werk, Dresden.
Argus bayonet 44.45    
Argus 33mm thread     Used on C3 models
Arriflex bayonet 52 54 (1982)
Arri PL breech lock 52 54.00 All PL=Positive Lock mounts are inherited from the Mitchell BNCR mount.
Arri Maxi PL breech lock 52 64.00 Similar to Arri PL except for diameter. Used on Arriflex 765. All PL=Positive Lock mounts are inherited from the Mitchell BNCR mount.
Asahiflex bayonet 45.46 37  

B4 bayonet 48 (air)   For 2/3″ video, both normal and HDTV. Mentioned here. A technical report from Sandia National Labs agrees.
Bolex breech 23.22    
Bolex H8RX 1″×32tpi thread 15.31 25.4  
Bronica S2A bayonet & 57x1 thread 101.7 57  
Bronica SQ bayonet 85 78 Leaf shutter in each lens
Bronica ETRS bayonet 69.0 ± 0.03   Measured to back of body (mount surface for film back); see service manual
Bronica GS1 bayonet      

C-mount 1″×32tpi thread 17.526 25.4 (0.69″)
C-S mount 1″×32tpi thread 12.526 25.4 According to Navitar, who should know. Thread is also known as “1-32 UN 2A.”
Canon EOS bayonet 44 54  
Canon EX1/2 VL camcorder bayonet 20    
Canon R/FL/FD breech or bayonet 42 48 42.1mm according to this list, 42.00mm according to Wikipedia, 42.13mm according to a Japanese list that seems to have vanished from the Web. The Canon service manuals of the time specify a “42.14 Dial Gauge”, whatever that might be, to adjust the flange distance
Canon screw M39x1 thread 28.8 39  
Contarex bayonet 46   No aperture ring on lenses; aperture set by control on body
Contax RF dual bayonet 34.85   Measured to outside of outer bayonet; see this page. Most lenses mount to inner bayonet and have no focusing helical; focus is in camera body. Lenses mounting to the outer bayonet (usually longer lenses) have focusing capability.
Contax/Yashica bayonet 45.5   This mount is very similar to the Pentax K bayonet; enough so that, like the mounts of the Retina Reflex and Voigtländer Bessamatic, modification is possible for compatibility
Konica Autoreflex bayonet 40.5   According to this page and this one. Markerink’s original list had it as 40.7.
Konica F bayonet 40.5    
Konica Hexar RF bayonet 28.00mm ± 0.03mm (pressure plate rails)
27.76mm (film rails)
  Designed for compatibility with Leica M lenses, but nominal distances are slightly different.
Kowa Six/Super 66 breech lock 79    

Leica M bayonet 27.95 44 Measured to pressure-plate rails. 27.76 to film rails. See this page for a discussion of the subtleties.
Leica R bayonet 47    
Leica S bayonet 50?   The Hasselblad H adapter looks to be around 10mm.
Leica screw M39x26tpi 28.8 39 This and the Visoflex mount are sometimes mistaken for M39×1mm, a tiny difference, but enough to cause problems with some non-Leica M39 lenses.
Leitz Visoflex I M39x26tpi 62.5 39 (91.30 total)
Leitz Visoflex II, III Leica M bayonet 40 44 (68.80 total)

M42 screw M42x1 thread 45.46 42 Used by Contax S, Pentax, Praktica, and many Yashica, Chinon, Cosina, Ricoh, and Soviet cameras.
Mamiya 7/7II bayonet ∼60 49 Diameter according to this measurement.
Mamiya 645 bayonet 63.3    
Mamiya RB bayonet 112.00   111.00 according to this message on
Mamiya RZ bayonet 105.00   108.00 according to this message on
Mamiya ZE bayonet 45.5    
Micro Four Thirds bayonet 19.25    
Minolta AF bayonet 44.5 49.7 variously listed elsewhere as 44.5, 44.6, 44.7; Konica/Minolta’s digital SLRs were taken over by Sony, who uses the same mount.
Minolta SR/MC/MD bayonet 43.72 +0.01 -0.02 41 Measured (I think) to pressure plate rails: see this service manual for specifics.
43.7 +0.02, -0 according to this page.
Miranda dual bayonet/screw 4-claw bayonet and 44×1mm screw mount 41.5   41.46 according to this list. Apparently the M44 thread originated in the first Miranda of 1954, and was retained for compatibility when a new bayonet was introduced. Starting in 1974, the "TM" models used M42, and a Miranda-branded K-mount SLR was sold in the U.K.
Mitchell BNCR breech lock 61.468 68 (1966)

Narcissus M24x1 thread 28.8 24  
Nikon 1 bayonet 17    
Nikon F bayonet 46.5 44  
Nikon rangefinder bayonet 34.85 49 Identical to Contax rengefinder mount, but with slightly different focusing cam.
Novoflex   100    

Olympus OM bayonet 46 46  
Olympus Pen F bayonet 28.95    

Camera System Mount type Register Diameter Comments
Panavision PV breech lock 57.15 49.50 (1972)
Paxette M39x1 thread 44    
Pentacon 6 breech lock 74.1   Identical to Exakta 66 and Kiev 60.
Pentax 6x7 bayonet 84.95   (74.10?)
Pentax 645 bayonet 70.87    
Pentax Auto 110 bayonet 27    
Pentax/Praktica M42x1 thread 45.46 42 add film thickness, and get 45.50mm...
Pentax K bayonet 45.46 44 Register identical to Pentax M42 mount
Pentax Q bayonet 9.2    
Pentina breech lock 45.5    
Praktica bayonet 44.4    
Praktiflex M40x1 thread 44.0    
Petriflex breech lock 43.5    
Petri bayonet 45.5   from this list
Praktica bayonet 44.4    
Praktina breech lock 50    

Rectaflex   43.4    
Ricoh breech mount 45.5    
Rolleiflex SL35 (QBM) bayonet 44.6 46 44.5mm according to Schneider, 44.7 according to another list that has since disappeared from the Web, 44.46 according to Wikipedia
Rolleiflex SL66 bayonet 102.8   according to this message on
Rolleiflex SLX bayonet 74.00    

Samsung NX bayonet 25.50    
Schneider M26x0.5    
Sigma SA inner bayonet 44   Similar to Pentax K, but incompatible. Rumor from China has the Sigma mount using the same electrical signals as the Canon EOS mount, with which it shares a register of 44.0 mm.
Sony Alpha bayonet 44.5 49.7 Variously listed elsewhere as 44.5, 44.6, 44.7; identical to Minolta AF mount.
Sony E bayonet 18    

T2 mount M42x0.75 55   Also T-mount, Sigma YS. T stands for "Tamron".
Topcon RE bayonet 44.7   Identical to Exakta, but with different mechanism for automatic diaphragm.
Topcon UV bayonet 55   Used on leaf-shutter cameras with shutter behind the lens.

Voigtländer Bessamatic bayonet 44.7   This is a leaf-shutter camera, but apparently designed with the shutter behind the lens, so the entire lens can be removed and used elsewhere. Someone will sell you an M42 adapter for this mount. The Bessamatic mount is so similar to that of the Kodak Retina Reflex that apparently it is possible to modify a lens to fit both cameras.

Yashica Pentamatic, Pentamatic II bayonet 43.00   This mount predates the M42-mount Yashica SLR’s, which were introduced in 1962. Judging by the photos of Exakta and M42 adapters found in the manual, the register is significantly less than the 45.46mm of the M42 mount. Not to be confused with the shared Contax/Yashica bayonet mount, which has a register similar to that of the M42 mount.

Wrayflex M41.2×26tpi 42.05    

ZM39 M39x26tpi 45.46 39 An oddity that apparently uses the Leica thread, but with the same register as M42. Used on Zenit 1, Zenit S, Zenit 3, Zenit 3M, and Kristall.
Zeiss Ikon Flektoskop, Flektometer screw 84.5   119.35 total: A rangefinder-to-SLR converter à la Leitz Visoflex
Zeiss Ikon Panflex   64.5   99.35 total: A rangefinder-to-SLR converter à la Leitz Visoflex
Zenit 80 multi start thread 74.1    

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Stephen H. Westin
Last modified: Fri May 15 19:55:58 EDT 2015