The Kistar 40mm f/2.4 lens already exists for Sony E-mount (see here and here) and the Leica M-mount version of the lens is currently under development according to the manufacturer Kinoshita Optical: 15% off Topaz Labs products with code RUMORS15 20% off ON1 products with code NIKONRUMORS 5% off  Funleader lenses with code LEICARUMORS $10 off Luminar with code … Continue reading New Kistar 40mm f/2.4 lens for Leica M-mount is currently under development