Here's a link to a handy little conversion program I use at work a lot. http://tinyurl.com/it7n
Dave On 8/24/05, Butch Black <[EMAIL PROTECTED]> wrote: > > The sigma is GN 50m @ 100ASA, 105mm zoom reflector setting. The Pentax > > one is GN 54m @ 100ASA, doesn't say what zoom that's at. > > If you multiply by 3 do you roughly get your guide numbers in feet? > > Butch > >
