Weston Model 617 Type 2 Leicameter Exposure Meter, 1934 USA manufacture.
From the early thirties, the innovative Leica camera developed and made by Leitz in Germany began to achieve world-wide popularity. Using 35mm cine film, it employed a horizontal travel cloth focal plane shutter. The speed settings on this were not in the standard linear progression common to Compur leaf shutters of the time, but had some arbitrary deviations and inclusions. Weston's special versions of the Model 627 loupe and Model 617 shown here were calibrated to support these values directly. Leicameter versions of the model 650 and 715 Master were manufactured later.
The Model 650 Leicameter is the most commonly available to the collector, although much rarer than the Universal or Cine Models. They sell for between five and fifteen times as much. This Model 617 is much rarer and I was very lucky to come across it and purchase it for a modest auction value.
It appears in Leitz catalogues under the designation LEDQA and E.Leitz of New York is clearly embossed on the dial face. Instead of the meter reading Candles per Square Foot, or relative light values, the scale is marked up in shutter speeds directly, for a reference film speed of 23 degrees Scheiner at f6.3. To translate this to other film speeds and apertures, the following procedure applies:
Set the inner outward facing pointer to the correct film speed on the outer rim of the dial. The inner most wheel is then rotated until the shutter speed indicated on the scale lines up with the outer inward facing pointer. Any desired combination of shutter speed and aperture can then be read off the dial.
The choice of Scheiner ratings is interesting. It had been conceived in the nineteenth century to rate sensitised plates used in astronomy. By 1934 it had fallen out of favour in Germany because of the lack of an absolute reference source in its calibration. In that year it was replaced by the D.I.N. system. The Scheiner system continued to be used world wide and in the USA in particular, for some time.
Never the less, it is a curious and possibly short sighted decision to use the Scheiner film rating system when Weston's own ratings were both well established and respected. The back of the Model 617 Leicameter (illustrated) shows some recommended ratings for a number of films. Weston would have published a booklet with ratings for a much wider range of contemporaneous films. The later Model 650 Leicameter was manufactured with Scheiner ratings and as a variant using A.S.A. speeds. The ASA and DIN systems became well established and are combined in the ISO standard in use up to the present day.
Apart from the kudos of a Leica owner being able to sport their own Weston meter dedicated specifically to their camera, it is difficult to see how the Leicameter makes life any easier than intelligent use of a Standard or Universal Weston. In any case, as Leitz standardised their shutter speeds on the later 'M' series of cameras, the need for a dedicated meter diminished.
So, they are few and far between and very very collectable. And I've got one.