Canon EF 85mm f/1.8 USM

Put this next to the 85mm f/1.2L and the L lens wins on rendering and loses on everything else. The f/1.2L is slow to focus, heavy, and costs four or five times as much. The f/1.8 USM autofocuses in a blink, weighs about a pound, and has lived in working portrait bags since 1992 because it is roughly a quarter of the price and gets the job done on a deadline. For a lot of shooters who started on Canon film bodies in the nineties, this was the first "real" portrait lens they could actually afford.

Wide open at f/1.8 it is sharp in the center with a little softness and glow at the edges, which on a face is a feature, not a flaw. Stop down to f/2.8 and it snaps into proper sharpness across the frame; by f/4 to f/5.6 it is as crisp as anything Canon made at this focal length. The out-of-focus rendering is smooth and rounded, helped by an eight-blade diaphragm, and the falloff from the plane of focus is gentle rather than surgical. Contrast is on the higher side, colors lean a touch warm, and it isolates a subject from a busy background the way a short tele should.

The honest weakness is chromatic aberration. Shoot it wide open against backlight, a chrome bumper, bare branches against a bright sky, and you will get purple and green fringing on the high-contrast edges. On color negative film it is usually mild enough to ignore at print sizes; on a contrasty slide it shows. Canon never put low-dispersion glass in this one, which is exactly why it stayed cheap. The later 85mm f/1.4L IS fixed the fringing and added stabilization, and that is the lens people cross-shop against it now if budget allows.

On a film body the f/1.8 maximum aperture is the whole point. Available-light portraits indoors, a theater, a dim reception hall, you can hold a usable shutter speed on 400 film without a flash. Meter for the face wide open and let the background fall where it will. Zone Light Meter will hold an incident or spot reading off the skin while you decide how much shadow to keep, which matters when you are working at f/1.8 and have almost no depth of field to spare. The 58mm filter thread is a common, cheap size, so a polarizer or a warming filter does not cost a fortune.

It is one of the easiest lenses in the entire EF lineup to recommend. Decades of weddings, headshots, and event work have gone through it, it adapts cleanly onto mirrorless bodies, and the used price stays low because Canon made so many. Buy it knowing the fringing exists, frame around hard backlight when you can, and it will outlast the camera you bought it for.