Not meaning to set myself up as an "expert" i beg to differ with the suggested exposure above, normally an exposure of approx 8 - 12 seconds using a 200 asa /Iso film with the camera set at F5.6 would be quite enough, the big danger of using such fast films as 1600 asa/Iso would be that of OVER exposure. Theres a few examples on my website if you wish to take a look, none of them are over 15 seconds, http://www.whitewolf1.moonfruit.com/