C4 Blue Cooling Color Correction
- Designed for Film Photographers
- Reduces Color Temperature by 350°K (-40 Mired Shift)
- Helps balance warm lighting conditions by adding blue cooling effect
- 6 layers of HMC multi-coating
- Equivalent to @82C Filter
- Description
The C4 color correction filter cools the ambient light entering the lens by 350° kelvin (-40 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 C4 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 type. Candles and low watt incandescent bulbs are examples of warm light sources.
You are shooting at sunrise or sunset with daylight-balanced film (5500° K) and the overall scene is too warm. The filter will help cool the scene for a more natural look.
HOYA Multi-Coat (HMC) filters are recommended for enhancing the performance of today’s multicoated lenses. These popular filters minimize reflection, reduce flare and ghosting, and result in over 97% average light transmission.
Comparison of C Series Filters:
FILTER
Cooling Amount
Equivalent C2
200°K (-20 Mired Shift)
82A C4
350° K (-40 Mired Shift)
@82C C8
1700° (-80 Mired Shift)
80C C12 2200° (-120 Mired Shift) @80A 
Exposure loss: 2/3 Stop Mired Shift -40 Equivalent Filter @82C Glass Type: Hoya Optical Number of Multi-Coatings: 6 total / 3 each side Hardened Top Layer: No Anti-Static: No Frame Construction: Low Profile / Aluminum Front Filter Threads: Yes