This is the original version of the 617.

The Leicameter is based on the Model 627 cine meter. The meter needle indicates the shutter speed to be used for a film speed of 23° Scheiner and an aperture of f6.3. A table on the side of the meter shows a multiplication factor for other film speeds and apertures.

This is an improved version of the 617 model.

The first Weston appeared in 1932 having two selenium cells. The 650 model which was smaller and had a rectangular body was introduced in c. 1934. A similar model calibrated specifically for cine work was introduced in 1937 called the 819. A model calibrated for the Leica was also produced. Production probably ended around 1940 with the introduction of the Weston Master range. The price was £5.18.6.

When using the cine model the film speed is set on the calculator dial which is then turned to match the f.p.s. to be used, the reading is then taken, the Relative Brightness value shown by the meter needle can then be found on the calculator which will point to the aperture to be used.

The Junior 850 is a simpler alternative to the Weston 650 and at £4 it was considerably cheaper. In use the light value is shown by a needle moving over a scale. That value is set against the emulsion speed by aligning a band showing light values with the emulsion speed shown on a fixed scale. The shutter speed and aperture pairs can then be read.

The 853 was an attempt to make Weston photoelectric meters more accessible by reducing the information shown and the steps required to take a reading. It was not entirely successful. The film speed is set against a choice of only two shutter speeds. On taking the reading the meter needle points to the aperture to be used. There is a small table to translate to other shutter speeds (1/10 - 1/200). For still and cine use. The method of setting the film speed is interesting, the speeds are marked on a metal plate, when the value is aligned to an index (the shutter speed) the plate moves over the selenium cell to a varying extent.