Pentax SMC Pentax-A* 85mm f/1.4 (K)

Pentax built this 85 to anchor the top of the K-mount line. The asterisk in A* was their professional star tier, reserved for the optics they wanted to stake a reputation on, and this one sat right alongside the best fast 85s of its day: Nikon's Nikkor 85mm f/1.4, the Contax Zeiss Planar 85mm f/1.4, Canon's FD 85mm f/1.2. For portraits at maximum aperture it earned a place in that company and has kept it.

Wide open there is a faint veil of glow over a center that is already sharp, the kind of softness that flatters skin instead of smearing detail. Stop down to f/2 and the glow burns off. By f/2.8 the middle of the frame is biting sharp. The bokeh is the reason people hunt these copies down. Out-of-focus highlights render as round, evenly lit discs without onion rings or hard edges, and the falloff from the focus plane is gradual rather than abrupt. Pentax's SMC multicoating holds contrast and color even with a bright source sitting just outside the frame, so it flares less than most fast glass of its generation.

It is a portrait lens before anything else. The 85mm length gives you working distance and the compression that flatters a face, and at f/1.4 you can wash a cluttered background into pure tone from across a room. Focus is manual, as it was on every A-series optic of its day. That matters less than you would expect, because the throw is long and smooth and easy to nail even wide open. Adapted onto modern mirrorless, it draws plenty of portrait and wedding shooters who want a softer, more painterly look than a clinical autofocus 85 gives them.

The honest weakness is longitudinal chromatic aberration. Shoot a backlit subject at f/1.4 and you get green fringing behind the focus plane and magenta in front of it, worst in specular highlights. It cleans up by f/2.8, but at maximum aperture it is there, and no amount of affection for the bokeh makes it vanish. If that bothers you, a fast autofocus 85 will out-resolve this lens on a chart and control the fringing better. It just will not render the same way.

Prices have climbed well past most autofocus 85s, which is what happens to a well-regarded fast prime in short supply. People pay it because the look is hard to replicate. One practical note for daylight work: at f/1.4 you run out of shutter speed in a hurry, so meter for the aperture you actually want and let Zone Light Meter tell you when you need an ND filter on the 67mm thread to hold that wide-open frame without clipping the highlights.