Pentax's WR macro — the D FA 100mm f/2.8 with enhanced weather resistance for outdoor macro.
The Pentax SMC D FA 100mm f/2.8 WR Macro is a weather-resistant macro prime from Pentax for the full-frame K-mount system. The D FA designation confirms digital-optimised full-frame coverage with autofocus motor compatibility, and WR indicates the 72-point weather and dust sealing shared with Pentax's weather-resistant body line.
The lens delivers 100mm at f/2.8 maximum aperture with 1:1 macro magnification, Pentax's SMC Super Multi-Coating, weather and dust resistance at 72 points around the barrel, Pentax K-mount screw-drive AF coupling, Quick-Shift manual focus override, and full-frame coverage.
Weather sealing in a macro prime is genuinely useful — macro photographers often work in damp outdoor environments with dewey grass, rain-covered flowers, and humid conditions where an unsealed lens would be at risk. The 100mm focal length provides natural working distance for most macro subjects. Pentax in-body SR applies to this lens when used with compatible bodies.
Test AF motor operation and verify Quick-Shift manual override works smoothly without engaging the AF motor. Test 1:1 macro focusing accuracy and sharpness at minimum focus distance. Inspect WR seals at the mount and around focus and aperture rings. Examine the front element for the cleaning marks common on macro lenses from close-proximity subjects.