>>3400106Don’t sweat it too much.
A flash meter is a normal light meter that *also* hasn’t flash metering. Most have a PC socket to trigger your flashes from the meter m (to take a reading), some don’t.
So apart from the flash metering function, a normal light meter has two modes: incident metering and reflected metering.
In incident mode, the white dome is covering the light sensor. Then you walk to where you subject is, point the meter to the camera (where you’ll be standing when taking the pic), and take a reading. This will give you a correct exposure regardless of the subjects reflectivity (Black cat in coal mine, white rabbit in snow, etc.) And you don’t have to do any thinking or use a grey card to get the right exposure.
The disadvantage is, you have to walk to where te subject is, and that’s not always possible. For instance when taking a landscape shot with far away mountains, or an architectural shot. But in studio or any controlled environment, people use incident mentoring pretty much exclusively.
In reflected mode, you slide the dome to the side and expose the light sensor. Then you point the meter towards your scene and you meter jut as you’d meter with the inbuilt light meter in any camera.
You try to point it to something resembling middle grey to get the correct exposure. You have to account for subject reflectivity though as usual, ie if you point it at something very bright and use those settings without adjustment you’ll get an underexposed shot.
Think of it like that: the light meter will try to convert everything it’s pointed at to middle gray: point it to snow, and it’ll give you an exposure that results in the snow being grey (and everything else underexposed). Point to a black building and it’ll result in an exposure turning the building grey and everything else overexposed.
Essentially all built-in light meters (phones, dSLRs) are reflected meters.
Lastly, there are lightmeters that also do spot metering.
