EF Mount

EF50mm f/1.0L USM

STANDARD & MEDIUM TELEPHOTO Lens

EF50mm f/1.0L USM
Marketed September 1989
Original Price 358,700 yen (w/case and hood)
Lens Construction (group) 9
Lens Construction (element) 11
No. of Diaphragm Blades 8
Minimum Aperture 16
Closest Focusing Distance (m) 0.6
Maximum Magnification (x) 0.11
Filter Diameter (mm) 72
Maximum Diameter x Length (mm) 91.5 x 81.5
Weight (g) 985

An ultra-fast standard lens with the largest aperture for SLR lenses in the world at the time. Two large-diameter ground and polished glass aspherical lens elements (3rd & 8th) provide high-contrast with low-flare image quality even at maximum aperture. Curvature of field is minimized through use of four high-refraction glass elements. Spherical aberration and curvature of field at close focusing distance are minimized by floating mechanism. A ring USM (Ultrasonic Motor) achieves silent, high-speed AF and full-time manual focusing.

Block diagram

  • Aspherical lens