25/09/2023
Around 1940, Cornu asked Aluvac to cast the bodies and backs of a small 24 x 36 camera in aluminum. These parts were marked Aluvac 3439 and Aluvac 3440.
These elements will be used for around twenty years by two companies to produce many popular device models.
The Société des Établissements Modernes de Mécanique Générale et de Décolletage Jean Cros was created in Saint-Étienne just before 1939 with state credits to support the war effort. Jean Cros had rocket fins molded by Aluvac.
After the defeat, Jean Cros, forced to refocus his activities in the civilian field, plans to launch into the construction of cameras. He contacted Paul Royet, who had been "specially assigned" to his factory until his demobilization, to offer him the position of Director of the photographic section, where absolutely everything had to be created.
In 1941, Jean Cros, director of the SEMM, obtained a license from Cornu to manufacture a device in Saint-Étienne from these parts. It is Paul Royet, future director of the SEM, who will carry out this project.
The Ontobloc follow on from the Reyna by abandoning the telescopic lens mount in favor of a rigid mount, which simplifies construction and avoids some problems when shooting. This is what the name Ontobloc means.
Ontobloc, which is almost a rigid Reyna II
Ontobloc II, where the integrated foundry viewfinder is replaced by a chrome cover, with a richer and less austere appearance
Ontobloc III, featuring a double helical focuser and a lens aperture at least 2.8.
In each of these models, we encounter numerous varieties, linked to artisanal construction and the supply difficulties of this post-war period.
The first Ontobloc I model retains the needle closure method of the Reyna and Reyna-Cross II.
The second model (built on the Sem-Kim case) has a hinged closure and an external lock.
