Pentax SMC Pentax-FA 43mm f/1.9 Limited (K)

The 43mm is the focal length nobody else bothered with, and that is the whole point. Pentax picked it because 43.27mm is the true diagonal of a 35mm frame, the actual "normal" lens by the textbook definition, not the 50mm everyone rounded to for a century. Pentax released it in 1997 as the first of the FA Limited trio, machined from aluminum with a clicking aperture ring and a metal hood that screws into the 49mm filter thread. It is the only Limited with a screw-in hood, a concession to how slim the barrel is. Small enough to vanish on a body, heavy enough in the hand to feel like a watch.

People pay nearly new money for clean used copies, and the rendering is why. Wide open at f/1.9 it is already sharp in the center with a gentle falloff into a smooth, slightly painterly out-of-focus field. Stop to f/4 and it snaps to clinical across the frame. The Pentax SMC coating keeps flare and ghosting down even shooting into a low sun, and the color comes back warm and saturated without going garish. Bokeh is round and quiet, never nervous, never the swirl you get from older double-Gauss designs pushed too hard. Focus falloff is gradual, which is what makes it flatter faces. The whole Limited family was tuned by judging prints by eye rather than chasing chart numbers, an approach Pentax credits to photographer Shoji Otake, and you can feel that priority in how the lens draws.

It lives in the hands of people who shoot one lens for everything: travel, street, environmental portraits, the family stuff that actually gets printed. The slightly long-of-normal angle is tighter than a 35 and wider than a 50, so it frames a person at conversational distance without you backing into a wall. On an APS-C Pentax digital body it becomes a roughly 65mm short telephoto and turns into a genuinely lovely portrait lens, which is partly why the line never died and Pentax kept making it into 2021.

The honest weakness is close focus. Minimum focus distance is about 0.45m, so this is not a detail or near-macro lens, and the field curvature shows up if you shoot flat subjects like brick walls wide open. You also pay a premium for the build and the cult status. A plain 50mm f/1.7 Pentax delivers most of the optical performance for a fraction of the price, and people who cross-shop this against a Voigtlander 40mm or a Zeiss normal are buying the metal and the rendering character, not raw resolution numbers.

Where it sits today is firmly in the boutique-prime tier, the lens Pentax shooters keep when they sell everything else. Loaded on a K-mount film body in dim interiors, meter it wide open at f/1.9 in Zone Light Meter to see exactly how much shadow you are holding before you commit, then stop down once you have the exposure you want. The reward for the price is a lens you can carry all day and never want to swap off, and that is a rare thing in a normal prime.