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Konica C35 AF favori envoyer Print
Photos by Sylvain Halgand text by Sylvain Halgand. From the collection of Sylvain Halgand
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Manufactured in Japon from 1978 until 0.
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Inventory number: 1519

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Konica C35 AF

Traduction de Sylvain Halgand.
 
In 1977, the launch of C 35 surprised AF everyone. One expected that Minolta was the first manufacturer to propose a 24 X 36 compact with automatic focusing. Konica won it. Since more than one year, it was a question of the Visitronic system, of Honeywell, but this one equipped only with the prototypes of cameras super-8 (Sankyo and Elmo) and of Pentax lens.
 
What is what the Visitronic system?
 
The camera is equipped with 5 openings in frontage: the lens, the window of the cell, the finder and two windows for the Visitronic system (also called VA/F for Visitronic Auto/Focusing). These two windows are of each side of the inscription Konica Auto Focus.
The system functions by triangulation, like a rangefinder and not by analysis of contrast.
 
 
Let us see initially the diagram assembly of VA/F in C 35 AF (these duplicated diagrams coming directly from Japan and the USA, overloaded with the pen felts, were photographed filtered, recalled, as well as possible possible). Subject (1), a mirror fixed at 45° (2) returns an image in VA/F (3). The rotary mirror (4), during release, leaves the adequate position which it occupies for a subject located at 1,1 m (approximately 43°) and turns with a perfect regularity towards the position that it occupies for a subject located ad infinitum (45°). During rotation,VA/F which compares the 2 images returned by the 2 mirrors, indicates the moment when it detects that 2 images out of the 2 sensitive cells which it comprises become identical. The 2 brushes converge at this moment on the subject. It is the principle of the rangefinder! … but classically, it is the eye which determines the moment of the superposition of the 2 images… whereas here it is VA/F which compares their identity.
At the moment when the mirror (4) started to turn, the lens (5) started to move back starting from the focusing to 1,1 m, towards the focusing ad infinitum, under the action of the spring (6). Mirror and lens traverse their race during exactly same time.
Let us return to VA/F, during the race, it indicates the moment of the identity of the 2 images to a “brain” (7). This one supplies instantaneously the electromagnet (8) which by engagement of the tilting pin (9), in the toothed rack (10) of the lens, stops the race of this one. The subject (1) is then at the point on the film (11).
The automatic photographic exposure meter having during this time measured the exposure, or with the flash the position of the lens controlling the diaphragm, release intervenes. Because automatic adjustments EE of the exposure and VA/F of the development are ensured during the travel of the release!!! ± 1/30 of S… A visible needle in a window on the right of the lens makes it possible to read, if it is wished, the adjustment used by the system of automatic focusing(control a posteriori).
At the time of the following winding, mirror and lens are repositioned on 1.1 meter… awaiting the following analysis…
 
 
 
VA/F is a whole of integrated circuits and optics sold sealed to the manufacturers who must associate the external components.
 
 
(sources: Phot' Argus n° 83 of November 1977)
Konica C35 AF