Should the lettering fade, flake away or get discolored, it is very easy to refresh with lacquer paint sticks (available at your local brick & mortar hobby store).
While a simple lens consisting of only 5 elements, the Leica 90mm F2 Summicron M APO is a very high performing lens and often considered amongst the M system's best lenses. In 1998 the Leica 90mm F2 Summicron-M APO was introduced.
The next Leica 90mm Summicron-M update in 1980 radically reduced the size and weight, bringing us the form factor still used today for the current APO version. Partly due to World War II, the world would not see its first Leica 90mm F2 Summicron M until 1957.
The 90mm focal length has been a staple of the classic Leica rangefinder system since 1937 with the market introduction of the 90mm F2.2 Thambar ( recently re-released by Leica). 5 Elements / 5 Groups, 1 Aspherical ElementĤ80 Grams / 16.1 Ounces (without lens caps)