I have a B&W 3 stop and a B&W 6 stop grad filters, my silly question is, is the 3 stop a ND 3 and the 6 stop a ND 6, if not could someone please let me know what the are.
I always thought a ND3 is a one-stop filter, a ND6 is a two-stop filter (because cameras tend to go up in 1/3 stop intervals). So ND4 = 1.33 stops, ND5 = 1.66 stops, etc. Using my presumption, a 3-stop filter would be ND9 and 6-stop filter would be ND18!
I'm no expert so maybe someone can correct me on that...
mercho no they are nd's, that's for your input