----- Original Message ----- From: "Paul Stenquist" Subject: Re: Hand Meters
> True. I've found that guide numbers are usually optimistic. If you're > shooting transparency film, they are generally not sufficiently accurate. If you are going to use GN for flash calculation, you need a flash meter to claculate the GN for the individual unit, and then you need to measure the guide number for the specific location, as GN can change if the you have reflective walls or not. William Robb