Lightmeters

[barrettyman]

I have an old light meter, I think I vaguely understand how it works if you can change the shutter speed

Comments

[rjstra]

Assuming its a stand alone light meter it should give you a combination of shutter speed and apeture e.g. 1/125th @ f8. As you reduce/increse the shutter speed the apeture moves in sequence. so you get the following corresponances.
1/500 - f/4
1/250 - f/5.6
1/125 - f8
1/60 - f/11
1/30 - f/16

Essentially as you half or double the shutter speed you increase/decrease the apeture by 1 f/stop. This keeps the amount of light in each exposure constant.