The Heliopan 105mm KB 15 (80A) Color Conversion Filter corrects color temperature shifts when shooting daylight film under tungsten and halogen lighting. This optical-quality glass filter neutralizes yellow color casts from 60–100W halogen ceiling fixtures and incandescent table lamps, preserving natural skin tones and accurate color reproduction. Perfect for indoor event, portrait, and documentary photography where unfiltered daylight film would render warm, unflattering results. A professional-grade solution for film photographers requiring precise color correction in artificial light environments.