Pentax Super-Takumar 105mm f/2.8

Wide open this lens renders skin with a soft, slightly glowing edge that sharpens into real bite by f/4. That transition is the whole character of the 105mm f/2.8 Super-Takumar. It is not a clinical optic and was never meant to be. It gives you a gentle out-of-focus field behind the subject, smooth and undistracting, with focus that falls off slowly rather than slamming shut the way a faster lens does. For head-and-shoulders work on 35mm, that is close to ideal.

It is an M42 screw-mount lens from the early Super-Takumar period, sold for bodies like the Pentax SV before the Spotmatic arrived. This is single-coated glass, made before the Super-Multi-Coated upgrade came around 1971, and the single coating matters. Shoot it into a window or a bright sky just out of frame and you will see veiling flare wash the contrast down noticeably. Hood it and the problem mostly disappears. Stopped to f/5.6 through f/11 the center is genuinely crisp, and the color leans warm and a touch low in contrast, the kind of rendering that flatters skin without much help in post.

People shoot it for portraits, mostly. A 105mm on 35mm is the classic compression length for faces, long enough to keep features natural and let you stand at a comfortable distance. It also works as a tidy candid lens for events and street where you want some working room. At the time it gave you a short tele for far less than the faster Nikon and Canon options of the same class, like the 105mm f/2.5 Nikkor, which cost meaningfully more.

The honest weakness, beyond the flare, is the focus throw. Like most Takumars it turns a long way from infinity to its closest distance, which is great for nailing precise focus on a static subject and frustrating when someone is walking toward you. The minimum focus is also fairly distant for a 105, so it is not a flowers-and-jewelry lens. If you want close, this is the wrong Takumar.

Today it sits in the cheap end of the adapted-glass world. Mount it on a mirrorless body with an M42 adapter and the rendering and build feel like a lot more than the money you spent, which is why it gets cross-shopped against the 105mm SMC version (better contrast, costs more) and against 85mm to 100mm Soviet and Japanese primes of the same vintage. People buy this one for the character, not the spec sheet.

One metering note. Because f/2.8 is your fastest aperture and you will often shoot it there for the bokeh, meter wide open in dim rooms and let Zone Light Meter place the skin tone where you want it before you commit, since the single coating eats a little contrast that your highlight reading should account for. The 49mm filter thread is standard and cheap, so a screw-in ND or polarizer for outdoor portrait work is easy to source.