Colour correction filters are used for colour balance adjustments and are used singly or in combination to change the overall colour balance. This Magenta colour correction filter will absorb green, thus reducing or removing green casts from images. Colour corrections are available in 8 different densities from 025 to 50. This 165mm filter is usable with Hitech 165mm holder systems or any 165mm holder. The filter is also available in 67mm, 85mm, 100mm and 150mm sizes. Hitech filters are made from the highest quality 1.5mm optical resin.