Pentax's dedicated full-frame macro — the D FA 100mm f/2.8 with weather resistance.
The Pentax SMC D FA 100mm f/2.8 Macro is a dedicated macro lens for Pentax K mount with full-frame coverage. The D FA designation confirms compatibility with both APS-C and full-frame Pentax bodies including the K-1. It provides true 1:1 macro magnification with the working distance advantage of the 100mm focal length. Weather-resistant construction adds practical value.
Optical performance is excellent for macro work. Sharpness at close distances is outstanding. At portrait range, the 100mm f/2.8 delivers very good results with pleasant bokeh. The flat-field design ensures edge-to-edge sharpness on flat subjects. SMC coatings provide good contrast. The lens doubles effectively as a portrait prime thanks to the flattering 100mm perspective.
Pentax K mount, full-frame (D FA). Filter thread is 49mm — very compact for a macro lens. Weight is approximately 340 grams — lightweight. Build quality is good with weather-resistant construction. Autofocus uses the body's screw-drive motor. Benefits from Pentax's in-body Shake Reduction stabilisation. The WR version adds enhanced weather sealing.
Available on the used market at reasonable prices. Check AF accuracy and smooth focus ring. An excellent macro lens for the Pentax system. The weather resistance, full-frame coverage, and in-body SR support make it genuinely practical. The 49mm filter thread and 340-gram weight are remarkably compact for a macro lens.