Pentax's SMC Macro-Takumar 100mm f/4 — a respected multi-coated M42 macro telephoto.
The Super-Multi-Coated Macro-Takumar 100mm f/4 is a macro telephoto prime made by Asahi Optical for the M42 screw mount in the early 1970s. It was the dedicated close-focusing macro lens of the Pentax M42 system, carrying Asahi's Super-Multi-Coating, and is regarded as one of the finer macro optics of the screw-mount era.
This is a manual-focus M42 screw-mount lens with a 100mm focal length and a maximum aperture of f/4, designed for close-up work with an extended focus helicoid. Focus is by hand and the aperture uses the automatic diaphragm. It is a well-built all-metal macro. Exact reproduction ratio and element figures are not asserted here beyond the verified focal length and aperture.
The 100mm macro focal length gives comfortable working distance for close-up subjects such as flowers, insects and small objects, and doubles as a short telephoto for portraits with pleasant rendering. This lens is respected for high sharpness and flat-field performance in the macro range, aided by its multi-coating for contrast against bright backgrounds.
This is a desirable Takumar macro and clean copies command higher prices. Check the long helicoid for smooth even focus over its extended travel, inspect the glass for haze and fungus, and confirm the automatic diaphragm functions with dry blades. An M42 adapter and appropriate close-up technique make it an excellent manual macro lens on mirrorless.