Hoya C2 Cooling Filter – 82A Color Correction for Warm Light warming filter The Hoya 85 filter is

The Hoya 85 filter is helpful when: You are using tungsten-balanced film (3200°K) and shooting in daylight

Exactly what you want from a Protector filter

These two filters are also available as a set

The Hoya W4 filter is helpful when:

Hoya C2 Cooling Filter – 82A Color Correction for Warm Light warming filter The Hoya 85 filter isDescription The C2 color correction filter cools the ambient light entering the lens by 200 kelvin ( 20 mired shift) by adding blue to the overall exposure. This filter helps fine tune the color or look of your scene to match your film's white balance. The Hoya C2 filter is helpful when: You are using tungsten balanced film and the light source is warmer than the traditional 3200 K and you need a specific amount of color correction to match your film