Pentax's fast Takumar fifty in M42 — the 55mm f/1.8 offering a stop more speed than the f/2 version.
The Pentax Takumar 55mm f/1.8 is the faster variant of Pentax's M42-mount standard prime, offering an extra stop of speed over the common f/2 version. As one of the most produced fast fifties in M42 mount, it was the standard lens for Pentax Spotmatic cameras when a faster aperture was desired. Both Super-Takumar and SMC Takumar versions exist.
Optical performance is good with characteristic Takumar warmth. Sharpness is acceptable at f/1.8 and good by f/2.8. The extra stop over the f/2 version provides useful additional light gathering and slightly shallower depth of field. Some versions use thorium glass that develops a yellow tint — correctable with UV exposure. Bokeh is smooth and pleasant.
M42 screw mount — universal adapter compatibility. Filter thread is 49mm. Weight is approximately 220 grams — compact. Build quality is excellent with precision metal construction. SMC versions have superior coatings. The auto/manual aperture switch on the barrel controls stop-down behaviour. Multiple optical versions exist across the long production history.
Common and affordable on the used market — slightly more than the f/2 version. Check for thorium yellowing, haze, and fungus. An excellent vintage fast fifty for M42 adapters. The extra stop over the f/2 version is worthwhile for low-light shooting. One of the best value vintage fast primes available.