ADavidhazy <andpph@xxxxxxxxxxxxxxxxxx> writes: >>Do they have a fair amount of neutral density, too? Just curious; I >>doubt I'll ever work with one. > > Right. I doubt any of us "regular" photographers will work with one > but of the nuclear bomb explosion photographs many were made with > just such a shutter. I've got Edgerton's book, with some of the *very* early bomb photos in it, and have read that and some other articles on how various things were done back then. > Inherent neutral density when they were supposed to be totally > transmissive did not really matter. Also they have a significant > transmission (well, this is also relative in terms of application) > when they are supposed to be opaque so they are most often used in > conjunction with a capping shutter of sorts - a mechanical one for > example. I'd guessed that the bomb photographs were the kind of place you'd need that kind of shutter speed, and that in that application a bit of neutral density wasn't going to be a big problem, yes. I remember reading about using explosives turn a sheet of glass to powder thus rendering it opaque in a very short time as one of the techniques used. > Kerr Cells are related to Pockels cells. -- David Dyer-Bennet, <mailto:dd-b@xxxxxxxx>, <http://www.dd-b.net/dd-b/> RKBA: <http://noguns-nomoney.com/> <http://www.dd-b.net/carry/> Pics: <http://dd-b.lighthunters.net/> <http://www.dd-b.net/dd-b/SnapshotAlbum/> Dragaera/Steven Brust: <http://dragaera.info/>
