Isomat Rapid
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| Agfa Isomat-Rapid (1965 -1969) image by Hans Jan Dürr (Image rights) |
The 1965 Isomat Rapid is one of Agfa's series of squared-off, largely plastic, "Iso" cameras made for their easy-loading Rapid film system. It outwardly resembles Agfa's other simple fixed-focus Rapid models like the Iso-Rapid I; and like those, it gives 16 square exposures of 24×24 mm per roll. A count-down frame counter indicates exposures remaining, and interlocks only allow the shutter to fire with the back closed and film advancing. (After the 16th exposure, the film advance will turn continuously but the shutter locks.)
But the Isomat Rapid is a more sophisticated model, with weightier body and a scale-focusing, three-element Color-Agnar 38mm f/4.5 lens. The feet/meter distance scale is inconveniently located underneath the lens, and instead simple pictograms face upwards towards the user. For two of these, the focusing scale has click-stop detents, but the "two heads" icon is strangely chosen: When focused at this distance, the lens's field of view is actually well over a meter/yard high.
While one might suspect that the "fly eye" panel beside the viewfinder would be a dummy light meter, this is a true selenium cell, which adjusts the aperture that the (diamond-shaped) lens aperture closes down to as the photographer presses the shutter release. If this aperture is within the available range of f/4.5–16, an indicator dot at the right side of the (not especially accurate) viewfinder switches from red to green, indicating proper exposure. The camera has a fixed shutter speed, nominally 1/70th second, in autoexposure mode.
For flash exposure (using the included hot shoe), a tab on the side of the lens permits manual selection of apertures; using these settings, the shutter speed switches to approximately 1/30th of a second, to accommodate the burning time of bulb flashes.
The Isomat Rapid takes advantage of one advanced feature of the Rapid film standard, namely its emulsion-speed index tab. When a photographer purchased a fresh roll of Agfa Rapid film, it would come loaded into a cassette indexed with a tab of the appropriate film speed, allowing a Rapid camera so equipped to adjust its meter readings. The indexing key is a silver metal plate affixed to the side of the cassette, whose central tab is shorter for slow films and longer for fast ones. (Empty cassettes of any speed could be used in the film take-up compartment: the emulsion type of an exposed Rapid roll was indicated by punched markings in the tail of the film.)
Rapid loads were standard perforated 35mm film, so today's photographer does not find it too daunting to reload them in a darkroom; but the speed-index system does create the extra headache of locating (or modifying) empty Rapid cassettes with the correct tab length.
