The latest M-lens release from Leica is an update of its famous 35mm 1.4 Summilux-M ASPH. Since this is a lens known for its sharpness, I concentrated my tests on architectural subjects with plenty of detail. My results show that this may be the sharpest lens ever made by Leica, and is, perhaps, the sharpest camera lens of all time. Although similar in design to its predecessor, this version has a floating element, and improved close focus.
Architectural subjects show remarkable detail (click here to download hi res image).
The Achilles heal of wide angle lens on full frame digital cameras is in the corners of the frame where the image is often soft unless the lens is stopped down to f/5.6 or more. Typically, these shorter focal lengths are also prone to vignetting and barrel distortion, but these aberrations are easily corrected in post-processing. My brick wall test on a full-frame Leica M9 showed some corner softness at f/1.4, less but still present at f2. but almost disappearing at f/2.8 -- all in all, very acceptable for a wide angle lens. At f/1.4 the brick wall test showed minimal vignetting, which disappeared when stopped down to f/2 and beyond.
Wide open at 1.4 the Summilux has a pleasing bokeh.
Close up at f/1.4 (click here to download hi res image).
The beauty of a 1.4 lens is shooting hand held at night.
Conclusion: Leica continues to improve its lenses for the greater demands of digital cameras while maintaining quality considerations for its older film M bodies. Other manufacturers often allow barrel and pincushion distortion along with vignetting in newer digital lenses on the theory that this is readily correctable with digital post-processing. Leica still has a loyal film camera user base where these corrections are not easily made.
Bottom line is that this is the sharpest lens I have ever used. Couple that with the high speed f/1.4 diaphragm and you have a real winner.