The Noctilux-M is among the world's fastest 35mm lenses. Its extraordinary optical performance is eminently suited for photography in low light situations and for producing photographs with extremely shallow depth of field. It produces outstanding contrast rendition, so that barely noticeable color differences are faithfully separated and the finest structures of the subject are resolved accurately, even under extremely unfavorable light conditions. The Noctilux-M gives Leica-M photographers capabilities that are beyond the reach of other outfits.
This lens has been updated with the "6-bit" coding, which allows the digital M camera to read this information optically and to identify which lens is being used. The camera can then (optionally) apply a "final stage" software based vignetting correction (for RAW images the lens used is simply recorded, no change is made).