The "natural speed" of most digitals is 200 ISO and there is no gain in image quality at 100 as opposed to 200 as there is with film - the opposite, if anything, is true. Granted there are times when it is necessary to drop below 200 for exposure reasons and the situation being debated here is one of them. My point is that there is no good reason to operate any digital below 200 ISO as a matter of course, particularly with modern studio stobes that can mostly be throttled back to at least 1/32nd power.
I agree with others who maintain that the image on the back of a digi is more useful, much cheaper and certainly quicker than Polaroids when setting up a shot for a film camera.
Having said that, it might be a good idea to start a thread on DPUG if anyone wants to continue the discussion about the exposure nuances of digital cameras lest we all get kicked off here before Christmas! OzJohn
I might suggest using polaroids. You'll have a record of the exposure, plus you can draw a map or write some details on the back of the print and store it away for another time as a reference.