Lux - Mono Monday 106

Lux is what your camera measures to calculate what it considers to be the correct exposure, though it doesn't express it like that of course. It's the metric unit for light emitted, reflected or transmitted by a surface.
Before the UK 'went metric' we measured this in foot candles (the motion film industry still does) and the numbers on the dial of that fine bit of British engineering, the Weston meter, indicate foot candles. The lowest number on the low light scale is 2, about 21.5 lux. My two Weston meters work as well as they did when they were made, the one shown in the late 70s, My other, a Master III, was made in the mid 50s. I use them regularly with my classic cameras.
The lux in principle is the amount of light on a surface one metre from a candle, but of course it's not that simple. You'd need a 'standard' candle, but a 'standard candle' is something else altogether, used to measure intergalactic distances
Thanks to MrsLinda for hosting Mono Monday this month.