Zeiss's compact M-mount wide prime — Biogon 25mm f/2.8 for Leica M rangefinders with T* coating.
The Zeiss 25mm f/2.8 Biogon ZM is a compact wide-angle prime for Leica M-mount using the classic Biogon optical formula. The ZM designation indicates Zeiss M-mount lenses — an affordable alternative to Leica's own wide-angle M primes.
Optically very good — the Biogon formula provides low distortion and even illumination. Sharp from f/5.6. T* coating for flare control. The 25mm is moderately wide on M — useful for street and environmental photography.
Leica M mount with rangefinder coupling. 46mm filter thread. Compact and lightweight — typical of Zeiss ZM lenses. All-metal construction. Manual focus. No electronic contacts — fully manual operation.
Available used at mid-range prices — significantly less than Leica's own 24mm or 28mm options. The Biogon formula is well-suited to rangefinder cameras. For budget-conscious M-mount users wanting Zeiss quality at 25mm.