A real veteran in Canon’s line-up, the Canon EF 50mm f/1.4 USM lens is 25 years old. It’s only about half the physical length of competing Sigma and Zeiss 50mm lenses, and just a third of the weight. That’s naturally a good thing for all of us who don’t like being weighed down by big, heavy lenses. The downside is that the lens feels basic, and a lightweight in features and performance.
The fact that it’s a ‘USM’ lens might sound like good news, but autofocus is based on an ultrasonic motor rather than being a ring-type system. It’s certainly not as quick or as whisper-quiet as the AF systems in many comparable lenses. On a plus point, this lens is unusual for a Micro USM system, in that it features full-time manual overdrive of autofocus.
Little luxuries include a focus distance scale which is absent on the more affordable Canon 50mm f/1.8 lens, and its aperture rating is two-thirds of an f-stop faster. This enables the use of a tighter depth of field, but that comes with its own perils in terms of performance.
In numerous samples of this lens that we’ve tested, autofocus accuracy has tended to be rather hit and miss. Sometimes it’s okay, but more often it’s not. The problem is particularly noticeable when shooting wide-open, where the depth of field is incredibly small and you need all the focusing precision you can get. Even when perfectly focused, sharpness is quite poor unless you stop down to at least f/2.8. Vignetting is also quite severe and, overall, it’s a lens that’s long overdue an update to bring it back up to snuff.
It bears a 58mm filter thread – larger than that of the Canon 50mm f/1.8 lens, which is 49mm. Overall it has a better, more durable build than the 50mm f/1.8, though it’s worth noting that there are still not weather seals – another point on which the lens could use an update.