I've just got hold of three dozen 4x5" holography plates, Agfa-Gevaert Holotest 10E75. Now I don't really want to start with holography. Old plate cameras are "madness" enough! So does anyone know if, and how, these can be used for photography? I assume they are very slow and very high contrast, but I also assume this can be remedied with appropriate processing. BTW, they'll be used two at a time in a Linhof Universal 4x5" film and plate holder, most likely in a Speed Graphic, and vrey likely with an assortment of strange old (barrel) lenses.