Canon's fastest EF autofocus prime — the rare 1989 50mm f/1.0L USM with aspherical optics.
The Canon EF 50mm f/1.0L USM was introduced in 1989 as part of the early EF autofocus system launched with the EOS mount. It was the first autofocus lens to reach an f/1.0 maximum aperture and remained the fastest autofocus lens Canon produced under the EF line. It was discontinued around 2000 and was never given a direct replacement, which is why it holds standing among collectors of the EF era.
This is an autofocus Canon EF lens with a 50mm focal length and an f/1.0 maximum aperture, driven by a ring-type ultrasonic (USM) motor. It uses aspherical elements in its optical formula and carries the red L ring designating Canon's professional line. The front filter thread is 72mm. It focuses down to roughly 0.6m and is a substantial lens, weighing near 985g. Verify the exact minimum focus and weight against the individual copy before listing.
At f/1.0 the lens produces a very shallow depth of field and heavy background separation, with noticeable softness and vignetting wide open that sharpens as it is stopped down. It suits portrait and available-light work where the extreme aperture is the point rather than corner-to-corner sharpness. The rendering wide open is soft and low in contrast, which many buyers seek out specifically for its look.
On the used market this lens commands high prices because of its rarity and the fact it was never replaced. Check autofocus performance carefully, as the early USM units can be slow and some copies hunt at f/1.0. Inspect for haze on internal elements, aperture blade oil, and smooth focus-ring action. Confirm the electronic contacts are clean so aperture and AF communicate with the body. Mounts natively on Canon EF bodies and adapts to Canon RF mirrorless with the official adapter.