Leica M mount
The oldest mount still in production and the only rangefinder system left. Every M lens since 1954 fits every M body, which is why a 1979 Summicron is a working lens rather than a museum piece. Two things shape the used market here: Leica reuses one product name across optical generations that trade at very different money, so the year matters more than the name; and the M9-generation CCD bodies have a sensor-corrosion history whose free-replacement programme has ended. Voigtlander is where most people actually buy glass.
25 bodies and 102 lenses tracked. Lowest used prices pulled daily from the major used-gear sites.
CCD bodies (2006-2012)
6 modelsThe M8, M9 and the first Monochrom. CCD colour at base ISO is the reason people still want them, and sensor corrosion is the reason to check service records before buying one. The M8 is APS-H and has no IR-cut filter over the sensor, so black fabric photographs magenta without a screw-in filter.
Monochrom bodies
3 modelsNo colour filter array at all, so every photosite reads luminance directly. Sharper and cleaner than converting a colour file, and permanently black and white. Leica has made one in every generation since 2012 and is the only company that does.
Screenless bodies
3 modelsThe M-D and M10-D have no rear screen — an ISO dial where it would be, DNG only, and no way to review a frame. Leica removing features and charging more for it, which the people who buy them consider the point.
CMOS bodies
13 modelsThe Typ 240 onward: live view, no corrosion history, and from the M11 a 60MP sensor with selectable 36 and 18MP modes. The M EV1 in 2025 replaced the rangefinder with an electronic viewfinder, which is either the future of the line or not an M at all depending on who you ask.