Why has this lens remained unchanged for 30 years? Most likely because even the extraordinary research and development team at Leica can't figure out a way to improve it! Produced by the equally famous Schneider Optic Works in Kreuznach to Leica specifications, the 21 f4 Super Angulon is the paramount super-wide angle lens. Exhibiting qualities such as corner to corner sharpness and even illumination, this is one lens that's bound to make a lasting impression. FEATURES INCLUDE: Retrofocus design Focuses as close as 8 inches (20.3cm)