Summicron 35 mm f:2,0 (I)

Características

Código - SAWOO 11008 (S), SAMWO 11108 (con anteojos), SAWOM 11308, 11104 11307-negro LLC - 151
Producción - 1958-1963, 577 rosca; 1958-1969 21,492 bayoneta (9557 con anteojos) < 36,150 total
Variantes - Negro (raro) o plateado; graduación en rojo o amarillo (después de 219xxxx) Anteojos:versión M2 sin, versión M3 con; Wetzlar y ELC.
Montura -Bayoneta Leica M y Rosca M39
Angulo de visión diagonal: 35mm (24 x 36 mm) -64º

Diseño Óptico:

Número de lentes/grupos 8/6
Longitud focal efectiva
Posición de la pupila de entrada

Intervalo de enfoque: - 0,7 m a infinito
Escalas: en metros o pies
Campo visual mínimo:430 x 640 mm - 390 x 590 mm (M3)
Factor de reproducción:
Diafragma - f/2,0-f/16 con click, valores intermedios, diafragma manual tipo iris de 10 hojas 11008 - 16 hojas 11308 & 11108
Montura de filtros: rosca interna E39
Parasol: 12571 IROOA - 12585 - 12538 - 12021
Visor: 12010 SBLOO

Longitud hasta la bayoneta - 28,4 mm
Diámetro máximo - 51 mm
Material: Latón plateado.
Peso - aprox. 170 g

Inscripción - SUMMICRON 1:2/3.5 LEITZ (WETZLAR or CANADA) 1XXXXXX
Diseñador: Walter Mandler

Referencias

• Ken Rockwell
  
• Thorsten Overgaard
  

Descripción

En la misma época que vió la introducción del Summaron diseñado por Leitz Wetzlar, al otor lado del Atlántico el centro de diseño de Leitz Midland produjo un objetivo Summicron (por definición f:2,0) que seguía el clásico diseño de doble Gauss pero añadiendo dos elementos.

El diseño Doble Gauss se define de la siguiente manera: un menisco positivo (convergente) es seguido por segundo menisco concavo con un indice de refracción menor y un mayor número de Abbe, el tercer elemento es similar, luego está el diafragma y el cuarto elemento es biconcavo de vidrio flint, y el quinto y el sexto son flints de forma concava. Estos elementos traseros son de mayor indice que los frontales.

Este diseño con 8 elementos tiene eleentos anterior y traseros relativamente grandes, presumiblemente para reducir el viñeteado. este objetivo es muy compacto y el equilibrio entre tamaño y calidad de imagen es evidente

The performance of the Summicron at maximum aperture is good, but of lower contrast than the Summaron version. Stopped down the image quality is excellent, as is the case with most Leica lenses. During the 1950s and 1960s a lens with an aperture of 1:2 was considered to be used only by professionals because they were assumed to work under the most demanding circumstances. While black-and-white material offered already high speed emulsions, this was not the case with color-slide film. Every additional increase in the speed of the lens was welcome and Leitz knew exactly the preferred deployment of the M-camera. The Summicron has also been made in L39 mount, but the low number of sales (some reports note that only 600 were made) indicate that the III-series in those days was reduced in status, but stayed the camera for the discerning amateur photographer.

This Summicron version has been sold in about 40.000 units. In 1969 an improved version was introduced. The total number of units should be related to a decade of effective production and in this view an average of 4000/year is a good result. These sales numbers may seem low when compared to current times where production often amounts to hundreds of thousands of units. In the 1960s however there was a much lower number of active photographers. Photography was the premium leisure activity to be sure , but also an expensive one and top class cameras and lenses had much higher price tags, compared to income levels than today. One should also take into account that during the 1960s the reflex camera emerged as the dominant camera system for amateurs and professionals.

The Summicron (I) 2/35mm has reached kind of a cult status, because of its subtle unsharpness gradient, that enhanced the impression of 3-dimensionality and its finish in the best Leitz tradition of fine precision mechanical workmanship.


Three Leica 35 mm Summicron por tango-, en Flickr