Paul Lange
Moderator
Here you will find a very handy exposure calculator for when you don't have a light meter. Its very easy to use and quite easy to make too. It is made available by Andy Lawn who based it on various other calculators found on the web but added his own little touch. I printed mine on some fairly thick photo paper and will soon coat it with clear sticky back plastic to protect it in case it gets wet.
Why is it useful? Some old cameras don't have light meters and unless you own a handheld one you need to know your exposure setting. Also it calculates exposure based on incident light which is the light available rather than the reflected light which is the light reflected back from the subject and is what in camera meters measure. In tricky lighting situations the calculator can be handy even if your camera has a meter.
Squit Photo
More reading:
RPF Guide to understanding the "Sunny 16 Rule"

Why is it useful? Some old cameras don't have light meters and unless you own a handheld one you need to know your exposure setting. Also it calculates exposure based on incident light which is the light available rather than the reflected light which is the light reflected back from the subject and is what in camera meters measure. In tricky lighting situations the calculator can be handy even if your camera has a meter.
Squit Photo
More reading:
RPF Guide to understanding the "Sunny 16 Rule"