Data sheet: Canon FDn 50 mm f/3.5 macro

Pekka Buttler, 01/2023

Specifications

The table below summarises the lens’ key specifications (measurements based on pictured sample):

Brand:	Canon	Lens name	Macro Lens FD 50mm 1:3.5
Focal length(s) 1	50 mm	Angle-of-view 2	46°
Maximum Aperture	f/3.5	In Production	1979–1987
Lens mount	Canon FDn	Subfamily (if applicable)	N/A
Length 3	60,1 mm	Diameter 4	62,6 mm
Filter ring diameter	52 mm	Weight	225 grams
Lens element count	6	Lens group count	4
Aperture blades (S/R/C) 5	6 S	Focus throw	320 °
Minimum focusing distance	23 cms	Maximum magnification	1:2
Has manual aperture ring	YES	Has Manual focus ring	YES
Aperture mechanism type	Automatic	Aperture click stops 6	3.5•5.6•8•11•16•22•32

Further notes:
• This lens was the short macro lens for Canon’s new FD system.
• Canon also introduced a 100 mm f/4 macro as well as a 200 mm f/4 macro lens as part of the new FD system. While the 50 mm and 100 mm new FD macro lenses were not ‘true’ macro lenses (they needed a dedicated extension ring to reach 1:1), the 200 mm f/4 was a true macro lens.
• The lens offers two magnification scales – one for use without the dedicated extension tube (FD 25), and another for use with the dedicated extension tube.
• Alike all traditional macro lenses, the lens focuses by moving the entire objective (set of lenses) away from the film plane. Hence the focusing to MFD entails a significant lengthening of the lens (see below).
• This lens features a bayonet for attaching a lens hood. The Canon BS-52 is the lens hood intended for this lens. On the other hand, because the front element is very deeply recessed (almost 40 mm), a lens hood is totally superfluous.

History of Canon FD lenses

Feel free to browse the JAPB article on the Canon FDn mount for all the details. Below is an outline of the position of the Canon FD mount in Canon’s development trajectory:

• 1959–1963: R-mount. Canon’s first SLR lens mount. Breech lock-type mount with aperture semi-automation (camera is able to stop down lens for taking the shot, but lens needs to be opened up by user action) .
• 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.

The era of the Canon FD and FDn mounts can be characterised by a gradual shift towards the ever-increasing use of plastics and lighter materials. In the chronology of this gradual shift:
• Chrome nose FD lenses (1971–1973) are solid metal (often brass), glass and (synthetic) rubber.
• Black nose FD lenses (1973-≈1975) are also metal, glass and rubber, but often 5-10% less heavy than chrome nose lenses.
• Late FD, (≈1975–1979) rubber is replaced by plastic and heavier metals are gradually replaced by lighter alloys
• With FDn lenses (1979–1987) this trend came to its natural conclusion as these lenses typically make extensive use of light alloys as well as, increasingly, plastics.
(In the EF era (1987 onwards) plastics fully take over)

A final, noteworthy aspect pertains to the S.C. and S.S.C. monikers found on some generations (Black nose and Late FD) Canon lenses: by the time of the introduction of the FDn mount Canon decided to do away with these markings. Hence, while FDn versions no longer sported the S.C. or S.S.C monikers, their coatings are always at least as good as that of their direct predecessor in the Canon FD line.

Related versions

Canon has a respectable history of manufacturing short macro lenses, that can be summarised (based on data from the Canon camera museum) as:

• FL 50 mm f/3.5 MACRO (1965–1973), 4 elements in 3 groups, 58 mm filter, 6 blades, 295 grams
• FDM 50 mm f/3.5 (1973–1979), 6 elements in 4 groups, 55 mm filter, 6 blades, 315 grams
• FDn MACRO 50 mm f/3.5 (1979–1987), 6 elements in 4 groups, 52 mm filter, 5 blades, 235 grams [this lens]
• EF 50 mm f/2.5 Compact Macro (1987–?), 9 elements in 8 groups, 52 mm filter, 6 blades, 280 grams
• RF 35 mm f/1.8 MACRO IS STM (2018-today), 11 elements in 9 groups, 52 mm filter, 9 blades, 305 grams

Interestingly, Canon never updated or upgraded the EF 50/2.5 compact macro (which dates back to the original introduction of the EF system), rather focusing on longer macro lenses and specialty lenses (such as the MP-E 65 mm supermacro). Similarly, Canon has not yet introduced a 50 mm macro for the new RF system, but has instead introduced 35 and 85 mm macro lenses.

Adapting

This lens cannot be used natively on any current SLR or dSLRs. To use it in its native environment, you will need a Canon FD or FL-mount film body. When doing macro photography on a Film SLR, remain mindful of effective aperture.

Thanks to being a fully manual lens (manual aperture, manual focus), the lens can be adapted to all mirrorless cameras using a suitable adapter. However, for the adapter to allow the lens to stop down, you will need an adapter that can be set to engage the FD lens’ aperture control lever.

Moreover, a large range of special adapters (helicoid adapters, tilt/shift adapters, speed boosters) for using Canon FD lenses on most mirrorless systems are available.

Using Canon FD lenses on dSLRs is a possibility, but is not problem free. Thanks to the relatively short flange focal distance of the Canon FD mount (at 42,0 mm, clearly shorter than that of any full-frame dSLR mount), any adapter will necessitate some optics to achieve infinity focus.

Footnotes

1. 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’. ↩︎
2. Picture angle is given in degrees 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 ↩︎
3. Length is given from the mount flange to the front of lens at infinity. ↩︎
4. Diameter excludes protrusions such as rabbit ears or stop-down levers. ↩︎
5. S=straight; R=rounded; C=(almost)circular at all apertures. ↩︎
6. Numbers equal aperture values on aperture ring; • intermediate click; – no intermediate click. ↩︎