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Leica R-System Mount

The Leica R-mount was introduced with the Leicaflex in 1964 to enable photographers to quickly change lenses on Leica's then new line of 35mm single-lens reflex cameras. It is a bayonet mount with three tabs around the base of the lens that fit into corresponding recesses in the camera's female part of the mount. The flange-focal distance amounts to 47mm. Most lenses with an R-bayonet can be used on any R-system camera body, but not all camera functions might be supported, as the mount has undergone several modifications over time.

Three cam lens
The location of the three cams[coocan.jp]

In particular, five different types of R-system lenses exist that differ in the way that they transfer aperture settings between the lens and the camera. This information transmission is achieved through a cam that is linked to the movement of the aperture control ring. The cam is in contact with another mechanism in the camera that is coupled with the meter, which makes it possible to mechanically transmit information on the selected aperture from the lens to the camera. Leica has over time switched from chrome-colored, curved cams (in German: Steuerkurven) to black, three-stepped cams (Steuernocken) supplemented by a ROM chip.

Single-cam lenses (1964-68): Lenses that were released in conjunction with the original Leicaflex had one curved chrome-bar between the mount and the rear lens element to transfer the aperture setting on the lens to the camera. These single-cam lenses (alternative called "one-cam" or "1-cam"-lenses) can be physically mounted on later Leicaflex SL and R-cameras, but the cam does not transmit the aperture setting to the newer cameras, so that only stop-down metering is possible. In other words, the aperture has to be closed down to the intended f-stop for the camera metering to work properly. However, Leica recommends not to use single-cam lenses on the R8 or R9, as heavy usage of the old lenses in the past might have led to a slight misalignment of the cam that could damage electrical contacts in the female part of the mount of the latest SLR cameras.

3-cam lens
Detail view of the second and third cam[leica-wiki.de]

Twin-cam lenses (1968-76): With the introduction of the Leicaflex SL that supported TTL-metering, Leica changed the lens-to-camera coupling mechanism and moved the curved cam to the opposite side of the lens mount. To nevertheless ensure that the newer lenses could also be used on the original Leicaflex, the first cam was maintained, resulting in twin-cam lenses (alternatively called "two-cam", or "2-cam" lenses). The first cam does not have any function on the Leicaflex SL, but is used to set the viewfinder display of the aperture in the Leicaflex SL2. Similar to single-cam lenses, twin-cam optics can also be used on R-cameras using stop-down metering, but are not recommended in conjunction with the R8 and R9.

Triple-cam lenses (1976-96): The R3, which was developed in cooperation with Minolta, introduced once again a different coupling mechanism. This third cam takes the form of a triple-stepped, black projection at the inside of the second cam. The first and second curved cams were maintained to ensure backward compatibility of the lenses. The resulting "triple-cam"-lenses (alternatively called "three-cam", or "3-cam" lenses) function on any Leica reflex camera in open-aperture mode, and can be used with the R8 and R9.

Rom lens
Leica ROM lens-mount with R-cam[kehblog.com]

R-cam lenses (1986-09): Ten years after the Leicaflex SL2 was discontinued, Leica started to produce R-lenses that only had the third, stepped cam, but lacked the first and second cams. These lenses would, hence, not transmit any aperture information to the Leicaflex/SL/SL2 models, and Leica indeed changed the shape of the lens mount slightly, so that these R-cam lenses (alternatively called "R-cam only", "R-only", "three-cam only", or "3-cam only" lenses) could not be mounted on the Leicaflex/SL/SL2.

ROM-lenses (1996-09): The R8 featured electronics that could take advantage of lens-specific information to correct for lens vignetting (in connection with the Leica Digita-Modul-R), to adjust the zoom reflector on flash guns according to lens focal length, or to correctly display aperture information if accessories, like tele-extenders, were attached to the lens. This lens-specific information was stored in a Read-Only Memory (ROM) chip that was added in the form of a strip of electrical contacts between the mount and the rear element of R-lenses. The ROM chip came with all newly sold lenses at the time, but could also be retrofitted by Leica technicians to older lenses. ROM-lenses have the R-cam and can also be mounted on R3-R7 cameras, where they support all the functions that these cameras offer.

Camera-Lens Compatibility

Before purchasing a pre-owned R-lens, it is worthwhile to carefully check its compatibility with one's camera. The following table provides a summary of the suitability of particular camera/lens-type combinations. Five different categories of compatibility exist: transmission of full aperture and lens information (marked "++" below), transmission of aperture information ("+"), stop-down metering only ("o"), not recommended ("[o]"), and impossible to mount ("-"). Some lenses with a long production history have appeared in several cam-versions, so that the lens' launch year (see second table below) is not a reliable indicator of its cam-specification.

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Compatibility of Leica R-lenses
# Leicaflex SL-SL2 R3-R7 R8-R9
1Single-cam+oo[o]
2Twin-cam++o[o]
3Triple-cam++++
4R-cam--++
5ROM--+++

That said, it is possible to have the cams of most (but not all) lenses upgraded in order to make an older lens fully compatible with newer cameras (or vice-versa). For example, a single-cam lens can be upgraded to triple-cam and an R-cam lens can be converted to triple-cam. According to Leica expert Douglas Herr, this service costs between USD 140 and USD 200 per lens. However, as the ROM chip occupies the same place in the lens mount as the first cam, it is not possible to use ROM-lenses on the Leicaflex Standard.

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Leica R-Mount Lenses
#  Lens
Designation
Focus
System
(type)
Lens
Construction
(elmts/groups)
Close
Focus
(m)
Filter
Type
(size)
Lens
Dimensions
(dia x len)
Lens
Weight
(net)
Used
Price
(USD)
Current
Offers
(USD)
1
 
Leica Super-Elmarit-R 15mm f/2.8 AsphMF13 / 100.18n84 x 85 mm710 g3500-7000i
2
 
Leica Super-Elmar-R 15mm f/3.5MF13 / 120.16n84 x 93 mm815 g2500-3500i
3
 
Leitz Wetzlar Fisheye-Elmarit-R 16mm f/2.8MF11 / 80.30n71 x 60 mm460 g500-1000i
4
 
Leica Elmarit-R 19mm f/2.8 (I)MF9 / 70.30E8288 x 60 mm590 g400-800i
5
 
Leica Elmarit-R 19mm f/2.8 (II)MF12 / 100.30n71 x 60 mm560 g1000-2000i
6
 
Leitz Wetzlar Super-Angulon-R 21mm f/3.4MF8 / 40.20S867 x 42 mm228 g400-800i
7
 
Leitz Wetzlar Super-Angulon-R 21mm f/4MF10 / 80.20E7278 x 44 mm420 g400-800i
8
 
Leica Vario-Elmar-R 21-35mm f/3.5-4.0 AsphMF9 / 80.50E6775 x 66 mm500 g800-1600i
9
 
Leica Elmarit-R 24mm f/2.8MF9 / 70.30S867 x 49 mm420 g300-600i
10
 
Leica Elmarit-R 28mm f/2.8 (I)MF8 / 80.30S763 x 40 mm275 g300-400i
11
 
Leica PC-Super-Angulon-R 28mm f/2.8MF12 / 100.30E6797 x 84 mm600 g500-1000i
12
 
Leitz Wetzlar Elmarit-R 28mm f/2.8 (II)MF8 / 70.30E5568 x 48 mm435 g350-500i
13
 
Leica Vario Elmar-R 28-70mm f/3.5-4.5MF11 / 80.50E6069 x 76 mm450 g300-600i
14
 
Leica Vario-Elmarit-R 28-90mm f/2.8-4.5 AsphMF11 / 80.60E6780 x 99 mm740 g1500-3000i
15
 
Leica Summilux-R 35mm f/1.4MF10 / 90.50E6775 x 76 mm685 g2000-3000i
16
 
Leica Summicron-R 35mm f/2 (I)MF9 / 70.30S768 x 61 mm510 g300-400i
17
 
Leica Summicron-R 35mm f/2 (II)MF6 / 60.30E5566 x 54 mm430 g400-600i
18
 
Leitz Wetzlar Elmarit-R 35mm f/2.8 (I)MF7 / 60.30S663 x 40 mm310 g100-200i
19
 
Leitz Wetzlar Elmarit-R 35mm f/2.8 (II)MF7 / 50.30S663 x 40 mm305 g200-300i
20
 
Leitz Elmarit-R 35mm f/2.8 (III)MF7 / 60.30E5566 x 42 mm305 g300-400i
21
 
Schneider-Kreuznach PA-Curtagon 35mm f/4MF7 / 60.30S870 x 51 mm310 g400-800i
22
 
Angenieux 35-70mm f/2.5-3.3MF11 / 111.00E5871 x 136 mm525 g500-1500i
23
 
Leica Vario-Elmarit-R 35-70mm f/2.8 AsphMF11 / 90.70E7788 x 133 mm1,050 g5000-10000i
24
 
Leica Vario-Elmar-R 35-70mm f/3.5MF8 / 71.00E6772 x 65 mm450 g300-400i
25
 
Leica Vario-Elmar-R 35-70mm f /4MF8 / 70.50E6074 x 79 mm505 g400-800i
26
 
Angenieux 45-90mm f/2.8MF15 / 101.00S869 x 122 mm774 g1500-2500i
27
 
Leica Summilux-R 50mm f/1.4 (I)MF7 / 60.50E5569 x 51 mm395 g250-500i
28
 
Leica Summilux-R 50mm f/1.4 (II)MF8 / 70.50E6070 x 51 mm710 g400-800i
29
 
Leica Summicron-R 50mm f/2.0 (I)MF6 / 50.50S663 x 39 mm680 g150-300i
30
 
Leica Summicron-R 50mm f/2.0 (II)MF6 / 40.50E5566 x 41 mm290 g400-800i
31
 
Leica Macro-Elmarit-R 60mm f/2.8MF6 / 50.27S7/E5568 x 62 mm400 g400-800i
32
 
Leica Vario-APO-Elmarit-R 70-180mm f/2.8MF13 / 101.70E7789 x 190 mm1,870 g4000-8000i
33
 
Angenieux 3x70 70-210mm f/3.5MF13 / 90.90E6280 x 164 mm783 g600-1200i
34
 
Leica Vario-Elmar-R 70-210mm f/4MF12 / 91.10E6074 x 157 mm720 g300-900i
35
 
Leitz Elcan-R 75mm f/2MF.. / ..0.70E6064 x 77 mm700 g3000-6000i
36
 
Leica Vario-Elmar-R 75-200mm f/4.5MF15 / 111.20E5570 x 157 mm725 g200-400i
37
 
Leica Summilux-R 80mm f/1.4MF7 / 50.80E6775 x 69 mm700 g2500-4000i
38
 
Leica Vario-Elmar-R 80-200mm f/4MF12 / 81.10E6071 x 165 mm1,020 g800-1600i
39
 
Leitz Wetzlar Vario-Elmar-R 80-200mm f/4.5MF.. / ..1.80E5572 x 157 mm710 g400-800i
40
 
Leica Summicron-R 90mm f/2MF5 / 40.70S7/E5570 x 63 mm560 g1000-2000i
41
 
Leica APO-Summicron-R 90mm f/2MF5 / 50.70E6070 x 59 mm520 g3500-5000i
42
 
Leitz Wetzlar Elmarit-R 90mm f/2.8 (I)MF5 / 40.70S765 x 72 mm500 g400-800i
43
 
Leica Elmarit-R 90mm f/2.8 (II)MF4 / 40.70E5567 x 57 mm450 g500-1000i
44
 
Leica APO-Macro-Elmarit-R 100mm f/2.8MF8 / 60.45E6073 x 105 mm760 g1500-3000i
45
 
Leitz Wetzlar Macro-Elmar-R 100mm f/4MF4 / 31.10E5568 x 120 mm670 g400-800i
46
 
Leitz Wetzlar Vario-Elmar-R 105-280mm f/4.2MF13 / 101.70S889 x 238 mm1,950 g3000-4000i
47
 
Leitz Canada Elmarit-R 135mm f/2.8 (I)MF5 / 41.50S765 x 91 mm655 g500-800i
48
 
Leica Elmarit-R 135mm f/2.8 (II)MF5 / 41.50E5567 x 93 mm730 g500-1000i
49
 
Leica APO-Summicron-R 180mm f/2MF9 / 61.50E100116 x 179 mm2,500 g8000-12000i
50
 
Angenieux APO IF 180mm f/2.3MF8 / 61.70E8286 x 149 mm995 g2500-4000i
51
 
Leitz Wetzlar Elmarit-R 180mm f/2.8 (I)MF5 / 41.80S878 x 134 mm1,325 g300-600i
52
 
Leitz Wetzlar Elmarit-R 180mm f/2.8 (II)MF5 / 41.80E6775 x 121 mm810 g300-600i
53
 
Leica APO-Elmarit-R 180mm f/2.8 (I)MF7 / 51.50S876 x 132 mm970 g2500-7500i
54
 
Leica APO-Elmarit-R 180mm f/2.8 (II)MF7 / 51.50E6776 x 132 mm970 g3000-8000i
55
 
Leitz Elcan-R 180mm f/3.4MF7 / 42.50E6063 x 115 mm750 g$$$i
56
 
Leitz Canada APO-Telyt-R 180mm f/3.4MF7 / 42.50S7.5/E6068 x 135 mm750 g800-1200i
57
 
Leitz Wetzlar Elmar-R 180mm f/4MF5 / 41.80E5586 x 100 mm540 g200-400i
58
 
Leitz Canada Telyt-R 250mm f/4 (I)MF6 / 54.50S8/E5566 x 100 mm1,380 g300-600i
59
 
Leitz Canada Telyt-R 250mm f/4 (II)MF7 / 61.70E6775 x 195 mm1,230 g400-800i
60
 
Leica APO-Telyt-R 280mm f/2.8MF8 / 72.50E112125 x 261 mm2,750 g2000-4000i
61
 
Leica APO-Telyt-R 280mm f/2.8 ModuleMF8 / 72.00rear125 x 276 mm3,740 g8000-12000i
62
 
Leica APO-Telyt-R 280mm f/4MF7 / 61.70E7788 x 208 mm1,875 g3000-6000i
63
 
Leitz Telyt-R 350mm f/4.8MF7 / 53.00E7784 x 286 mm1,820 g500-1500i
64
 
Leica APO-Telyt-R 400mm f/2.8MF11 / 94.70rear125 x 314 mm6,240 g10000-15000i
65
 
Leica APO-Telyt-R 400mm f/2.8 ModuleMF10 / 83.70rear157 x 344 mm5,800 g10000-15000i
66
 
Leica APO-Telyt-R 400mm f/4 ModuleMF9 / 72.15rear157 x 382 mm3,860 g6000-12000i
67
 
Leitz Wetzlar Telyt 400mm f/6.8 MF2 / 13.60S778 x 384 mm1,830 g500-1000i
68
 
Leitz Wetzlar MR-Telyt-R 500mm f/8MF5 / 54.00E7787 x 121 mm750 g800-1200i
69
 
Leica APO-Telyt-R 560mm f/4 ModuleMF11 / 83.95rear157 x 382 mm6,360 g12000-18000i
70
 
Leica APO-Telyt-R 560mm f/5.6 ModuleMF9 / 72.15rear125 x 374 mm4,050 g10000-15000i
71
 
Leitz Wetzlar Telyt-R 560mm f/6.8MF2 / 16.40S798 x 530 mm2,330 g400-600i
72
 
Leica APO-Telyt-R 800mm f/5.6 ModuleMF11 / 83.90rear157 x 442 mm6,550 g15000-20000i
73
 
Leitz Wetzlar Telyt-S 800mm f/6.3MF3 / 112.50built-in152 x 790 mm6,860 g3000-7000i
74
 
Minolta RF Rokkor-X 800mm f/8 for Leica RMF.. / ..8.00rear127 x 178 mm1,960 g1000-2000i

Further Reading

On a separate page, you will find a comprehensive compendium with the key specifications of all the R-system cameras. Moreover, if you need further detail, you might want to check out the selected Leica brochures that are available for free download, or consult your R-camera's manual. Last, but not least, the Leica family tree provides a visual impression of the evolution of Leica's cameras over time.

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