Thursday, July 5, 2018

Argus A2F (1939-1941)

International Research Corp. produced roughly 40,000 Argus A2F cameras in Ann Arbor, Michigan, from 1939 through 1941. It is the same as an Argus A with the addition of an extinction light meter and a focusing lens mount. The lens is an uncoated f/4.5 anastigmat in a self setting leaf shutter on a helical focusing mount. The focusing mount would let you get as close to your subject as 15 inches. At that range you would measure the distance from the subject to the camera using a tape measure. The aperture settings are marked from f/4.5 to f/18 in geometric steps. The shutter runs from 1/25 second to 1/200 second, also in geometric steps, plus bulb and time. The shutter release is a plunger that is threaded into the shutter, instead of a lever as on the earlier Argus A. The plunger can be unscrewed and replaced with a cable release. The plungers on these cameras frequently go missing. The film was the standard 35mm size cassette that is still available today.

Front

Back

Top

Film Chamber

On the top of the camera is an extinction meter the photographer could use to estimate exposure settings. The extinction meter has a sliding cursor and six openings backed by a strip of film having a graduated gray scale. You adjust the cursor according to the Weston speed of the film and the general light conditions. You hold the camera at arm's length and look through the extinction meter at the scene. You then slide the cursor to the darkest opening that you could clearly see and read the shutter speed and the aperture from the table and cursor. The result might be as accurate as using your photographer's eye, that is to say just guessing.

Weston film speeds were published by the Weston Electrical Instrument Company for use with their photoelectric exposure meters. The Argus has film speed settings from 12 to 72. Weston 12 speed is about the same as ISO 15 speed and Weston 72 speed is about ISO 90 speed, which were typical of film speeds when the camera was new. Eventually extinction meters were superseded by the photoelectric light meters made by Weston and other manufacturers.  Photographers started to use ASA speeds instead of Weston speeds about 1948.








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