Leica's compact ultra-wide for M — the Super-Elmar 21mm f/3.4 ASPH with premium correction.
The Leica Super-Elmar-M 21mm f/3.4 ASPH. is a premium wide-angle prime from Leica's M-mount lens line, carrying the Elmar designation that indicates a maximum aperture below f/2. The modest f/3.4 maximum aperture is a deliberate optical design choice enabling exceptional corner-to-corner sharpness and minimal distortion in a compact package.
The lens delivers 21mm at f/3.4 with aspherical optical elements, rangefinder focus coupling for use with M-mount rangefinder bodies, full-frame coverage, and Leica's M6-bit coding for automatic lens identification on digital M bodies. Manual aperture and focus with characteristic Leica damped ring action.
At the extreme wide end of the M-mount range, the Super-Elmar 21mm f/3.4 prioritises optical quality over aperture speed — its corner sharpness and distortion control are hallmarks of the design. For landscape, architectural, and street photographers who value clinical rendering over low-light aperture, the f/3.4 is an acceptable trade-off.
Verify rangefinder coupling accuracy across the full focus range — wide-angle lenses on rangefinder bodies depend on precise cam calibration. Check the 6-bit coding contacts if used with a digital M body. Inspect all element surfaces for coating damage or cleaning marks, and confirm aperture blade operation.