I have a Weston Master Universal Exposure Meter. There are some things on the face of it that I don't know what they mean. For instance, on the dial that moves to indicate the f/stop, there are the following letters: U, A (1/2 beneath it), C (2x beneath it) and O. U and O are for under- and overexposure, I think, but what are the A and C for? :confused:
Also, around the edge is a scale which is labeled as Light. What is that? :confused:
For Color film, A and C represent the narrower exposure range associated with color slide film.
For B/W film, A indicates "Absence of Contrast" and C indicates "Contrast." A is a convenient way of halving the exposure for flat scenes where C provides double the exposure for very contrasty scenes.
Light is the scale where you transfer the needle reading "light values" to the exposure dial.