Overview

The Sigma Mirror 400mm f/5.6 is a vintage catadioptric lens with mixed reviews. Optically, it can occasionally deliver sharp images in good light, but resolution is unexceptional and it suffers from purple/pink chromatic aberration in harsh light. Colors may appear flat (MFlenses). Build is solid but the lens hood slides out easily; manual focus is very difficult. It is best suited for patient photographers who enjoy the challenge of a quirky lens and can work in bright conditions, but most users will find it frustrating for consistent results.