FD 300mm f/2.8 Fluorite / L

Canon’s fluorite story is older than this lens. The company synthesised its first calcium fluoride crystals in 1967 and put two of them in the FL-F 300mm f/5.6 of 1969, the first consumer interchangeable lens to use the material. A fast version followed in the FL mount in February 1974, the FL 300mm f/2.8 S.S.C. Fluorite at ¥390,000, without the automatic diaphragm and full-aperture metering that the FD mount allowed. The FD 300mm f/2.8 S.S.C. Fluorite of October 1975, at ¥420,000, is the museum’s stated improvement on that lens: the same six elements in five groups and the same 112 mm by 230 mm barrel, now with full-aperture metering and an automatic diaphragm, a new bearing arrangement in the helicoid to make the focus light, and a diaphragm unit Canon had considered too difficult for a lens this large. It weighs 1,900 g, stops down to f/22 through nine blades and focuses to 3.5 m. The FD 2× Extender was developed alongside it so that the pair would work as a 600mm f/5.6.

The lens is black with a green ring, the marking Canon put on its fluorite glass before the L designation existed. That matters for identification because the second lens, the New FD 300mm f/2.8 L of April 1981 at ¥470,000, is a different object in every respect: grey-white with the red L ring, the New FD rotating mount, nine elements in seven groups counting a plain protective front glass, a UD glass element and one of fluorite, and rear-group focusing so the barrel holds its 245 mm length from infinity to a closer 3 m limit. It is 127 mm across and 2,310 g on Canon’s table, 2,348 g on Phillip Reeve’s scale. Filters drop into a rear holder in a dedicated 48 mm size; the hood is built in with an extension hood on top of it; the tripod collar is built in and revolves to vertical in one movement. Minimum aperture is f/32, in half stops.

Reviewers of the L agree on the same things. Phillip Reeve found it very sharp in the centre and mid-frame from f/2.8, corners good wide open and best by f/8, and chromatic aberration suppressed to a degree he compares with lenses thirty years younger; vignetting is 0.8 stops wide open and gone by f/4. Yat Ho Tsang calls it sharper wide open than many good 50s and finds colour fringing negligible from f/5.6. The one optical complaint, from Reeve, is flare, and the hood is not optional in backlight. The non-optical complaint is universal: five pounds is a tripod or monopod lens.

The 1975 lens has fewer reviewers and a slightly different reputation. A Canon Classics user rates its image quality a full ten, sharp at every aperture and free of colour fringing, and values the long focus throw for precise work; R. Flynn Marr, with an unused boxed example, reports excellent sharpness and minimal distortion but soft contrast at f/2.8. The one direct comparison, on MFlenses, found the two similar in centre sharpness at f/2.8, the Fluorite darker and contrastier and about four-fifths of a stop slower in transmission, and the L better in every mechanical respect: tripod collar placement, focus feel, close focus. The poster kept the L.

Buying one: look for scratches or clouding at the front element; on the 1975 lens make sure the removable tripod mount is present, since the lens is not usable on a tripod without it, and check that the extending helicoid runs freely through its long travel; on the L, work the rotating mount and the revolving collar, and confirm the 48 mm drop-in holder and extension hood are with it. No serial table or production figure exists for either version. Marr reads the date code R1007 on his S.S.C. Fluorite, serial 10775, as October 1977, and that is the only decoded example in the sources consulted. The months and yen prices rest on the Canon Camera Museum alone, and Wikipedia’s FD 300mm page could not be reached from this container.