Response to More on film speeds

I could probably find this on the web in 10 minutes of searching, but I think the answer might be of more general interest.
Does anyone know, offhand, what the relationship is between the exposure in Lux-seconds to get 0.1D over base + fog, and the ISO rating? That is, there should be a simple multiplier or constant to arrive at the ISO speed from the 0.1D+B+F exposure figure. Anyone know exactly what it is?
From rough estimation it appears to be somewhere in the region of 250000, but I'm suffering from a hangover this morning, so that figure might easily be a mile off!

[ Previous | Next ]