The Tiffen 6.6 x 6.6" 82C Light Balancing Filter allows you to increase the colour temperature by 400K to slightly cool the image to match the colour quality of the lighting. By using an 82C filter, you will be able to achieve a 3200K balance when the dominant light source is 2800K. The cooling effect of this filter requires a 0.6 stop increase in exposure for normal results. This filter is manufactured using ColorCore technology, a process that involves laminating the filter substrate between 2 pieces of optical glass and grinding it flat to a tolerance of 1/10,000th of an inch. It measures 6.6 x 6.6" / 167.6 x 167.6 mm. - Light balancing filter increases colour temperature and produces a cooling effect. - Adds 400K to achieve a 3200K colour balance from 2800K lighting. - Filter factor of 1.5 requires a 0.6 stop increase in exposure. Specifications