Canon EF 24mm f/1.4L USM

Canon built this in 1997 for the people who could not stop down. EOS had been around a decade, the FD mount was dead, and the working press had migrated to the autofocus 1-series bodies. What they did not have was a fast wide that could open up in a dim arena or a candlelit reception. The 24mm f/1.4L USM filled that hole. It was the wide end of a fast L prime family meant for reportage, and it stayed in the catalogue until the Mark II replaced it in 2008.

Being a 24mm on a reflex body, the layout is retrofocus by necessity. The rear group has to sit far enough from the film plane to clear the swinging mirror, so the design runs front-heavy and physically large, with aspherical elements correcting distortion. Ring-type USM drives the focus, fast and silent, which mattered when you were tracking a subject moving toward you down a hallway.

Wide open it behaves like a fast wide of its era. The center is genuinely sharp at f/1.4, contrast holds up, and the falloff into a blurred background is pleasant for a focal length this short. The trouble is the corners. There is real coma on point light sources, so streetlights and stars at the edge of the frame smear into little wings, and the extreme corners stay soft until you reach f/4 or f/5.6. Vignetting at full aperture is heavy. This is the lens the Mark II was built to fix, and it did, with SWC coating taming flare and a reworked design cleaning up the corners. The first version flares more readily into the light than you would like.

So who actually used it. Photojournalists and documentary shooters who needed one stop more than the f/2.8 zoom gave them, and environmental portrait people who wanted a wide field with a subject that still pops off the background. On full-frame film it is a true 24mm, generous but not cartoonish, which is why it reads as a reportage tool rather than a landscape lens. Stop down to f/8 and the corner story stops mattering. It becomes a perfectly good general wide.

On the used market it sits in the awkward spot of any superseded L glass. The Mark II is the better lens optically and not always much more expensive, so the Mark I sells cheap and people cross-shop it against the Sigma 24mm f/1.4 Art. You buy this one for the build, the USM, and the L rendering at a discount, knowing you give up clean corners and clean stars.

One practical note. The reason you bought f/1.4 is to shoot in the dark, so meter wide open. Set f/1.4 in Zone Light Meter when the room is dim, read the shutter it hands you, and stop down later if the scene allows. The 77mm front thread is standard L size, so your existing ND and grad filters carry straight over.