Overview

The Olympus Zuiko Auto-S 40mm f/2.0 is a rare, compact pancake lens praised for its extreme portability and solid center sharpness wide open, improving slightly when stopped down. However, it exhibits barrel distortion and visible vignetting at f/2. Build quality is high, but handling is compromised by an integrated filter thread in the aperture ring. Optically, it does not surpass the Zuiko 50mm f/1.8 or 35mm lenses. It suits collectors or those seeking the smallest OM lens, but as a user lens, cheaper alternatives like the 35mm or 50mm are recommended.