Often it is necessary or desirable to balance the light intensity in one part of a scene with another. This is especially true in situations where you don't have total light control, as in bright contrasty landscapes. Exposing for the foreground will produce a washed-out, over-exposed sky while exposing for the sky will leave the foreground dark and under-exposed. Lee Grad ND filters are part clear, part neutral density (available in grades of .3 (1 stop), .45 (1.5 stops), .6 (2 stops), .75 (2.5 stops), .9 (3 stops)). They allow the transition to be blended into the scene, often imperceptibly.
Lee Graduated Neutral Density Blenders are graduated over the entire 6" length of the filter.
Lee graduated resin filters are 4 x 6" (100 x 150mm) x 2mm thick. The 6" length allows for adjustment of the filter within the holder.
Neutral Density factors:
ND.3 (exposure adjustment = 1 stop)
ND.45 (exposure adjustment = 1.5 stops)
ND.6 (exposure adjustment = 2 stops)
ND.75 (exposure adjustment = 2.5 stops)
ND.9 (exposure adjustment = 3 stops)