The Hoya 46mm W2 Umber Color Correction Multi-Layer Glass Filter is a professional photographic accessory designed to adjust color temperature by adding a subtle warmth effect to images. This 46mm diameter filter increases the color temperature by exactly 200 Kelvin, corresponding to a shift of +20 Mired, and produces a bright amber tone that enhances color fidelity and exposure accuracy. Made from high-quality optical glass with multiple anti-reflective coatings, the filter achieves over 97 percent light transmission while minimizing stray light and ghosting for optimal image sharpness and contrast. Ideal for use with daylight-balanced films requiring a white balance of 5500K, this filter effectively corrects cooler lighting conditions, such as those encountered in overcast weather, shaded landscapes, or mixed lighting environments. Portrait photographers benefit from the warm, flattering tones it imparts to skin, resulting in naturally looking outcomes. The robust glass construction ensures long-term reliability and consistent performance under various shooting conditions. Compatible with all lenses with a 46mm thread, this warming filter serves as an essential tool for photographers seeking precise color temperature control without compromising optical quality or introducing unwanted artifacts.