This filter combines an 81ef with a 0.3 hard edge graduated filter. The 81 series of light amber (warming color temperature conversion filters) lower color temperatures and create a warming effect that reduces blues. These filters are used for more subtle changes in color balance. They are therefore often referred to as light compensation and not as conversion filters. The 81 reduces the colour temperature from 3800 K to 3200 K. ND degree filters are clear in the lower half of the filter with a gradual transition to the ND effect in the upper half. They are mainly used for light reduction in skylines of landscape shots. Graduated NDs are available in Soft Edge or Hard Edge variants. Soft edge gradations have a smooth transition from clear to ND. Hard edge graduations have a more defined hard-lined transition and are usually used for longer focal lengths. ND degrees are manufactured in different densities according to the degree of light reduction from 1/3 to up to 4 light levels. The 0.3 filter reduces light by 1 stop. This 85mm filter works with Hitech 85mm mounting systems or any 85mm (3.35"/P size) holder.