Overview

The Pentax SMC 100mm f/4 Macro is a well-built manual lens (1977-1984) with all-metal construction and engraved markings. It offers 0.5x magnification, extendable to 1:1 with tubes. Optically, it is very sharp edge-to-edge with minimal distortion and smooth bokeh, but loses contrast against bright light and has a hexagonal aperture that can be distracting when stopped down. The focus ring has a long throw for macro but is somewhat stiff. It suits those wanting a compact, versatile telephoto and macro lens, though its f/4 aperture limits portrait use.