F-Day 2x Filter E 40,5 coated slim version

The Heliopan 40.5mm F Day Filter is color correction filter allowing the use of daylight-balanced film with fluorescent lighting. The slight pink-purple tone of the filter eliminates the greenish hue caused by fluorescent bulbs and corrects it for approximately 5500K. This filter has a filter factor of 4, requiring approximately 2 stops of compensation for normal exposure.