APO-Summicron-M 90mm f/2 ASPH

Before the 75, the 50, and the 35 came this: the 1998 APO-Summicron-M 90mm f/2 ASPH, one of the M system's first apochromatically corrected lenses (alongside the APO-Telyt-M 135mm, also shown in 1998) and the design that announced Peter Karbe's benchmark era. Chromatic aberration effectively vanished; portrait shooters gained a wide-open sharpness the pre-ASPH 90s never had.

Still in production decades later, it remains the reference M portrait lens — and the ancestor every later "APO" in this catalogue descends from.