The Heliopan 28mm KB-15 (80A) Filter is a color conversion filter that helps to increase the color temperature from 3200 to 5500K. The 80A allows you to use daylight-balanced film in tungsten lighting without any color casts due to the lighting.
There is a 4x filter factor with this filter, requiring an increase of 2 stops for normal exposure. It has a 28mm brass mounting ring that is painted a matte black to help reduce reflections. The SH-PMC multi-coated Schott glass provides greater contrast and reduced reflection compared to uncoated filters.
