|Weston Master II|
with incident light invercone
Weston was founded by chemist Edward Weston, who held many patents for electrical inventions, from permanent magnets through cellulose manufacturing, dynamos, arc & filament lights and the magnetic-drag speedometer to electrical measurement instruments (and even US 895218 - a fruit box!) Weston's son, Edward Faraday Weston, applied for a U.S. patent on the first Weston Exposure meter, granted as No.2016469 in October 1935. This was a cylindrical case with an electrical meter at one end, and an iris at the other; an adjustable scale around the meter opened and closed the iris, and showed the exposure. Sangamo was originally "Sangamo Electric Co.", in Springfield, Illinois, and set up a British subsidiary in 1921. Sangamo acquired the Weston Electrical Instrument Co. in 1936.  Since Weston were an early player in the light meter game - before film speeds were standardised, Weston had their own film speed scales.
|Weston Master V|
The EuroMaster light meter is now being made by a company called Megatron.
- Weston Master article by David Haardt
- Weston Light Meter Manuals (PDF) : Photo-Manuals.com
- Weston meter manuals at www.orphancameras.com
- Weston Master V instruction manual on Mike Butkus' site
- Megatron - current manufacturers of EuroMaster
- Patent 2016469 Exposure Meter
- Patent 2046665 Exposure Meter
- Patent 2203209 Exposure Meter
- Several articles about Weston meters in James Ollinger's Exposure Meter Collection.
- 1950 advertisement for the Weston Master II