Canon New FD 24mm f/2

Most 24mm lenses of the manual-focus era stopped at f/2.8. Canon built this one a full stop faster, and that stop is the whole reason to own it. f/2 on a 24mm let you hand-hold a church interior or a dim street back when ISO 400 was fast film and there was nowhere else to buy light. The f/1.4 L got the glory and the aspherical element. This was the version working photographers could actually afford.

It belongs to the New FD line Canon rolled out in 1979, the black, lighter-bodied redesign that shipped multicoated as standard (Canon stopped badging "S.S.C." because every New FD lens already had it). Like any wide built for an SLR, it is a retrofocus design, built with enough back focus to clear a swinging mirror. Center sharpness is there from f/2. The corners are not. Shoot a brick wall wide open and the edges go soft and a little smeary; by f/5.6 they fall into line, and from f/8 the whole frame bites.

Color and contrast are classic Canon FD, slightly warm, held together well against flare unless you aim it straight into the sun. At f/2 with close focus you get more subject separation than a 24mm has any business giving, over a background that stays mostly calm. Stopped down it becomes an environmental documentary lens, the focal length you reach for when you want the room in the frame and not just the face. Street and photojournalism originally. Now a lot of filmmakers who adapt FD glass to mirrorless bodies for the price and the look.

The honest flaw is coma. Point sources in the corners, streetlights and stars, sprout little wings wide open, so the astro crowd that came for the f/2 speed has to stop down to f/2.8 or f/4 to clean them up, handing back the exact advantage they wanted. There is visible barrel distortion too, the usual retrofocus tax. Neither hurts a face or a sidewalk. Both show up in architecture and skies.

Canon orphaned the FD mount in 1987 when EOS arrived, so this glass never reached a native Canon digital body and is a nuisance to adapt to EF. On any mirrorless it drops on with a dumb adapter and behaves perfectly, which is what kept it alive. People cross-shop it against the Nikkor 24mm f/2 and the rarer, pricier Olympus OM 24mm f/2; the Canon is usually the value buy of the three. One practical thing: at 24mm you can hold a far slower shutter than a 50mm would forgive, so in a dark room, meter the shadow you actually care about and let the aperture sit at f/2. Zone Light Meter hands back a speed you can shoot without a tripod.