The Pentax HD DA 20-40mm f/2.8-4 ED WR Limited is a high-quality standard zoom for APS-C Pentax DSLRs. Key features include:
Great for landscape and street photography, and portraiture
Fast, nearly silent autofocus with full-time manual focusing
Excellent image quality and edge-to-edge sharpness
Durable, high-quality build
Standard Zoom. With a focal length equivalent to 30.5 to 61.5mm after sensor-crop factor, the Pentax 20-40mm is a great zoom option for Great for landscape and street photography, and portraiture. It offers a decent f/2.8-4 aperture that gives users some flexibility in indoor lighting conditions, but you’re not going to be using it to shoot in the dark.
Direct-Current Autofocus Motor. The in-lens direct-current motor enables smooth, silent autofocus performance for both stills and video. It also features Pentax’s Quick-Shift Focus System for instantly switching from autofocus to manual focus.
Optics. The eight group/nine-element design features one Extra-low Dispersion element and one super-low dispersion element for maximizing resolution with high edge-to-edge sharpness. Additionally, the Super Protect coating on the front and rear lens elements repels dust, water, and grease.
HD Lens Coating. The Pentax HD DA 20-40mm is treated with the PENTAX-developed HD coating. It provides a high-grade, multi-layer coating that reduces reflections and allows the user to capture contrasty images without flares and ghosting.
High-Quality Build. It features a durable aluminum-alloy barrel with seven special seals to keep out water, moisture, and dust.