The Lee 4x4" Neutral Density (ND) 0.9 ProGlass Filter enables the shooter to adjust exposure without affecting color balance. Neutral density filters are available in 1, 2, 3, or 4 stops to suit individual situations.
Neutral Density filters have several uses and offer the possibility to achieve otherwise unachievable results. ND filters appear grey and reduce the amount of light reaching the film. They have no effect on color balance.