So I was just playing around and shot my first roll of b&w white last weekend and processed it tonight. And to my surprise about half of the frames have now come out completely black, and the others were all perfect. Could it be: a.)my filters, i was playing around with some filters at the time, does my camera (EOS Elan) automatically compensate for that or do i have to take that into account and set what it should be against my light meters "better judgement"? b.)my meter is screwy? c.) i just plain screwed em up?