The Hoya 55mm C2 Blue Cooling Color Correction Multi-Coated Glass Filter is a high-quality optical accessory for photographers using lenses with a diameter of 55 mm. This filter creates a cooling effect of 200 Kelvin with a Mired shift of -20, adding a blue tint to images for color balance correction when using tungsten-balanced film (3200 Kelvin) under warm light sources such as incandescent bulbs or candlelight. It also effectively cools scenes when shooting daylight film (5500 Kelvin) during sunrise or sunset photography. The HOYA Multi-Coat (HMC) technology minimizes reflections, reduces lens flares and ghosting, achieving an average light transmission of over 97 percent for optimal image sharpness and clarity. Made from high-quality optical glass, this filter preserves color accuracy and maintains lens performance. The multi-coating technology ensures minimal light loss and maximum contrast under various lighting conditions. This color correction filter is particularly useful for professional photographers who require precise color temperature adjustments without compromising image quality. The 55 mm threaded design ensures compatibility with a wide range of standard photography lenses. Its robust construction and advanced coating technology provide reliable performance for both studio and outdoor shooting. This filter represents a practical solution for photographers seeking accurate color reproduction and enhanced optical performance in challenging lighting situations.