APO-Summicron-M 75 mm f:2,0 ASPH

Características

Código - 11 637
Producción - 2005 - 1,653+ ejemplares
Variantes -
Montura - Bayoneta Leica M con Códigos 6 bits
Angulo de visión diagonal, horizontal, vertical: 32°, 27°, 18°

Diseño Óptico:

Número de lentes/grupos - 7/5 un elemento con una superficie asférica, grupo flotante posterior
Longtud focal efectiva - 51.6 mm
Posición de la pupila de entrada -30.1 mm (respecto a la primera superficie de lente en la dirección de la luz)

Intérvalo de enfoque: - 0,7 m a infinito
Escalas: combinada, metros/pies
Campo visual mínimo:169 mm x 254 mm
Factor de reproducción: 1:7

Diafragma - f/2,0-f/16 con click, valores intermedios, diafragma manual tipo iris DE ? hojas
Montura de filtros: rosca E49
Parasol: Telescópico

Longitud hasta la bayoneta - 66.8 mm
Diámetro máximo - 58 mm
Material: Alumino
Peso - aprox. 430 g
Inscripción - APO-SUMMICRON-M 1:2/75 ASPH. E49
Diseño:

Referencias

• Erwin Puts: Leica Apo-Summicron-M 1:2/75mm ASPH
  
• SteveHuff
  

Descripción

Since the introduction of the Summilux-M 1:1.4/75 mm in 1980 this focal length has created a loyal following of photographers who like the subtle separation of figure and ground that is just more pronounced than with the 50 mm focal length.

To incorporate the additional frame for the 75mm in the rangefinder window the mechanism had to be redesigned and this change was partly responsible for the flare issues that for a period have plagued the rangefinder window after the introduction of the M4-P, the first body that could accept the 75mm lens.

The Apo-Summicron-M 1:2/75 mm ASPH is a very-high-contrast-very-high-definition lens with a very flat image plane. This is unusual for a high speed lens because an optical system comprised of curved (spherical = being part of a sphere) elements, produces generally a curved image surface. Technically the reduction of the Petzval sum is needed to correct this aberration. This is difficult to accomplish, but the liberal use of the high index glasses with anomalous dispersion, the use of the floating element and of an aspherical element all add up to the solution for the reduction of the Petzval sum and of the chromatic errors.

At full aperture the definition of extremely fine detail is outstandingly good from centre to edge. Stopping down to medium apertures improves contrast some crispening of the finest recordable detail. Veiling glare is totally absent and the lens produces deep black shadows with clean separation of subtle shadow detail. The internal blackening of the mount and the black paint on the ring-sets of the lens elements effectively reduces secondary reflections and halos around specular highlight spots are not detected.

This Summicron 75mm operates with the solid smoothness that is the defining property of the current generation of Leica lenses. The lens is heavy for its size, but the weight of the special glass types asks its toll. A small set of one Leica M body with two lenses (Elmarit-M 2.8/28 ASPH and Apo-Summicron-M 2/75 ASPH) would be sufficient to produce pictures of the highest possible quality in almost every situation, And the set would fit in a small bag. If you could compare this set with the historical set of Hektor 6.3/28 mm Hektor 1.9/73 mm the quantum leap in performance will be evident.