Kodak 3 x 3" (75mm) #96 Neutral Density (ND) 1.0 Wratten 2 Gel Filters have several uses, and offer the possibility to achieve otherwise unachievable results. They enable the shooter to adjust exposure without affecting color balance. ND filters appear grey and reduce the amount of light reaching the film.
Neutral density filters are available in 1, 2, 3, or 4 stops to suit individual situations. Determining which neutral density filter yields ideal results for any given lighting situation takes knowledge, experience and a collection of such filters. Generally speaking, the 2-stop value (ND 0.6) effectively compensates average situations.
Neutral Density factors:
ND .10 (exposure adjustment = 1/3 stop)
ND .20 (exposure adjustment = 2/3 stop)
ND .30 (exposure adjustment = 1 stop)
ND .40 (exposure adjustment = 1 1/3 stops)
ND .50 (exposure adjustment = 1 2/3 stops)
ND .60 (exposure adjustment = 2 stops)
ND .70 (exposure adjustment = 2 1/3 stops)
ND .80 (exposure adjustment = 2 2/3 stops)
ND .90 (exposure adjustment = 3 stops)
ND 1.0 (exposure adjustment = 3 1/3 stops )
ND 2.0 (exposure adjustment = 6 2/3 stops)
ND 3.0 (exposure adjustment = 10 stops)
ND 4.0 (exposure adjustment = 13 1/3 stops)