The Leica APO-Summicron-M 35mm F2 ASPH is an impressive piece of glass, boasting a complex optical construction consisting of 10 elements in 5 groups, with 4 aspherical surfaces. Six elements employ anomalous partial dispersion glass to help reduce chromatic aberration. At $8195 this is a costly lens, but from our first impressions, it is a significant cut above the older, well-established (and substantially cheaper) Summicron-M 35mm F2 ASPH, while remaining extremely small and lightweight.
In addition to offering very good image quality, the new APO-Summicron is capable of a genuinely useful close focus distance of 30cm (11.8″). This is substantially closer than any previous standard Leica M-mount lens, but in order to focus accurately between 0.7-0.3m on an M-series rangefinder, you will need to be in live view mode.