Pekka Buttler, 09/2023
Specifications
The table below summarizes the lens’ key specifications:
| Brand: | Canon | Lens name | SUPER-CANOMATIC LENS R 50 mm 1:1.8 |
| Focal length(s) 1 | 50 mm | Angle-of-view 2 | 46° |
| Maximum Aperture | f/1.8 | In Production | 1959–1964 (all versions) |
| Lens mount | Canon R | Subfamily (if applicable) | N/A |
| Length 3 | 46,8 mm | Diameter 4 | 64,6 mm |
| Filter ring diameter | 58 mm | Weight | 299 grams |
| Lens element count | 6 | Lens group count | 4 |
| Aperture blades (S/R/C) 5 | 6 S | Focus throw | 260 ° |
| Minimum focusing distance | 60 cms | Maximum magnification | 1:9,9 |
| Has manual aperture ring | YES | Has Manual focus ring | YES |
| Aperture mechanism type | Semi-automatic & manual | Aperture click stops 6 | 1.8-2-2.8-4-5.6-8-11-16 |
Further notes:
• The Canon R (Canomatic/Canonflex) mount launched Canon into the SLR business. While the line of cameras (and lenses) was not especially successful (overshadowed by the contemporary introductions from Asahi, Minolta, Nikon and others), it still did well enough for Canon to launch its successor the FL mount in 1964.
• Information on the Canon R mount is relatively scarce, and the availability of lenses is generally relatively weak.
• During those ≈5 years, Canon made three variants of the Canon R 50 mm f/1.8 lens. While the first (1959–1960) and third version (1963-1964) are outwardly very similar, the second version (1960-1963) had the two aperture rings grouped closer together. Due to the weak availability of data I cannot be 100% certain, but I deduce that the pictured sample is of the last type (some sleuth-work with serial numbers is involved).
• Canon R lenses have dual aperture rings, where the front ring sets the aperture in semi-automatic mode (sets the aperture the camera should stop down to) while the rear ring is a direct-coupling, clickless manual aperture ring. See more on the operation of Canon R lenses in the JAPB article on the Canon R mount
• The pictured sample is clearly radioactive, with a rear lens element being the likely culprit.
The history of Canon R lenses
Canon is undoubtedly one of the great names in 35 mm SLR photography. Ever since the 1959 introduction of the Canonflex – Canon’s first interchangeable lens SLR – Canon has constantly focused on being at the forefront of Camera innovation. Often this has necessitated taking stock and redesigning both cameras, lenses and lens mounts. Unlike its archival Nikon, Canon has not tried to integrate all novel features in the same lens mount, but has instead repeatedly launched new, modified mounts to facilitate new features, while still often (but not always) managing to maintain a decent degree of backwards compatibility.
In short (a longer version is here), the development of Canon SLR mounts can be traced as follows:
• 1959–1964: R-mount 7. Canon’s first SLR lens mount. Breech lock-type mount with aperture automation (camera is able to stop down lens for taking the shot.
• 1964–1969: FL-mount. Breech-lock type mount, physically similar mount as Canon R-mount, but camera-to-lens communication linkages somewhat different. Cannot communicate selected aperture to body (stop-down-metering only).
• 1970–1978: FD-mount. Breech-lock mount. FD lenses compatible with FL-cameras and vice versa. Manual focus lenses that communicate aperture information to camera, hence opening the door for automatic exposure (both shutter priority and aperture priority possible)
• 1979–1986: new FD-mount (a.k.a. FDn). Bayonet mount, backwards compatible with FL and FD mounts. Otherwise, as FD mount.
• 1987–today: EF-mount. Electronically controlled autofocus lenses that use an internal focusing motor. Compatible with previous mount lenses only using an adapter with optics.
Related versions
Canon has a long history of manufacturing f/1.8 50 mm lenses, that can be summarised (based on data from the Canon camera museum) as:
• R 50 mm f/1.8 (I) (1959–1960), 6 elements in 4 groups, 58 mm filter, ? blades, 295 grams
• R 50 mm f/1.8 (II) (1960–1963), 6 elements in 4 groups, 58 mm filter, ? blades, 305 grams
• R 50 mm f/1.8 (III) (1963–1964), 6 elements in 4 groups, 58 mm filter, ? blades, 295 grams [this lens]
• FL 50 mm f/1.8 (I) (1964–1968), 6 elements in 4 groups, 48 mm filter, 6 blades, 228 grams [data sheet]
• FL 50 mm f/1.8 (II) (1968–1971), 6 elements in 4 groups, 48 mm filter, 6 blades, 280 grams
• FD 50 mm f/1.8 chrome nose (I) (1971–1971), 6 elements in 4 groups, 55 mm filter, 6 blades, 305 grams
• FD 50 mm f/1.8 chrome nose (II) (1971–1973), 6 elements in 4 groups, 55 mm filter, 6 blades, 305 grams [data sheet]
• FD 50 mm f/1.8 S.C. (I) (1973–1976), 6 elements in 4 groups, 55 mm filter, 6 blades, 255 grams
• FD 50 mm f/1.8 S.C. (II) (1976–1979), 6 elements in 4 groups, 55 mm filter, 5 blades, 200 grams
• FDn 50 mm f/1.8 (1979–1987), 6 elements in 4 groups, 52 mm filter, 5 blades, 170 grams [data sheet]
• EF 50 mm f/1.8 (I) (1987–1990), 6 elements in 5 groups, 52 mm filter, 5 blades, 190 grams [data sheet]
• EF 50 mm f/1.8 (II) (1990-today), 6 elements in 5 groups, 52 mm filter, 5 blades, 130 grams
• RF 50 mm f/1.8 STM (2020-today), 6 elements in 5 groups, 43 mm filter, 7 blades, 160 grams
Adapting Canon R lenses
Firstly, Canon R/Canomatic lenses can only be used natively and with all intended features on original Canon R (Canonflex) bodies. While these are far less numerous than the subsequent FL and FD bodies, the original Canonflex’ were generally well-built and functioning copies are not impossible to come by.
If you’re using a mirrorless camera, Canon R lenses can be adapted using a Canon FD–>[your system] adapter. However, adapting Canon R lenses using a vanilla Canon FD adapter will – with many Canon R lenses – pose issues. The reason for this is that this Canon R lens (just as with some other Canon R and Canon FL lenses) has ‘the bulge‘ – it protrudes so far into the mount, that the placing of the aperture engage pin in most adapters does not allow the lens to be mounted. The solution for this problem is rather simple: buy another Canon FD-> [your system] adapter and remove the pin. Thereafter you will be able to use your Canon R lens on a mirrorless camera without issues. See more in this JAPB article.
Should you feel like trying your Canon R lens on a dSLR, you can expect some trouble. First – due to the short flange focal distance – you will have to either forgo being able to focus on anything close to infinity, or get an adapter with corrective optics. Next, you will have to remove the aperture engage pin from the adapter to be able to fit your Canon R lens. Finally – depending on the Canon R lens and the design of the particular adapter with optics – it may be that the rear of the Canon R lens will collide with the adapter optics, hence making it impossible to mount your lens.
Footnotes
- Focal length is (unless stated otherwise) given in absolute terms, and not in Full-frame equivalent. For an understanding of whether the lens is wide/tele, see ‘Angle-of-view’. ↩︎
- Picture angle is given in degrees (based on manufacturers’ specs) and concerns the diagonal picture angle. Rule of thumb:
> 90 ° ==> Ultra-wide-angle
70–90 ° ==> Wide-angle
50–70 ° ==> Moderate wide-angle
40–50 ° ==> ‘Standard’ or ‘normal’ lens
20–40 ° ==> Short tele lens
10-20 ° ==> Tele lens
5-10 ° ==> Long tele lens
< 5 ° ==> Ultra-tele lens ↩︎ - Length is given from the mount flange to the front of lens at infinity. ↩︎
- Diameter excludes protrusions such as rabbit ears or stop-down levers. ↩︎
- S=straight; R=rounded; C=(almost)circular at all apertures. ↩︎
- Numbers equal aperture values on aperture ring; • intermediate click; – no intermediate click. ↩︎
- The Canon-R mount should possibly be renamed to (or referred to) as the Canonflex mount to avoid confusion with the modern mirrorless mount that is sometimes also referred to as the Canon R mount.
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