Overview

The Carl Zeiss Jena Flektogon 20mm f/4 is a super wide-angle lens with a cult following, praised for its outstanding image quality and solid all-metal build. It is an epoch-making retrofocus design that enabled wide-angle SLR photography. Optically, it is sharp when stopped down to f/8 or f/16, but wide open at f/4 it is softer than the f/2.8 version, with noticeable vignetting. The lens has smooth, buttery focus and is a joy to handle. It suits landscape and architecture photographers who use a tripod and can stop down, but for astrophotography the f/2.8 version is recommended.