Overview

The HD Pentax DA AF 1.4X AW Rear Converter increases focal length by 40% with a one-stop aperture penalty. Optically, it reduces sharpness, especially wide open, but delivers outstanding sharpness stopped down to f/5.6 (Pentax Forums). Chromatic aberration increases noticeably along high-contrast edges, while corner illumination improves. Build quality is excellent with weather sealing and a lightweight 126g design. Autofocus slows in low light. It suits Pentax users needing extra reach without significant weight, particularly with sealed lenses.