The Hoya 46 mm W12 Umber Warming Color Conversion Glass Filter with multi-coating is a precise optical accessory designed to adjust color temperature for enhanced photographic results. It warms ambient light by 2200 Kelvin, corresponding to a Mired shift of 120, and gives images a rich dark amber tone. This filter is particularly effective with tungsten-balanced films like Cinestill 800T, helping to achieve a naturally warm appearance in outdoor daylight or with 5500 K light sources such as flashes and studio strobes indoors. Compared to the W10 model, the W12 offers a stronger warming effect for a more neutral look with standard tungsten films. The multi-coated glass construction minimizes reflections, reduces stray light and ghosting, and ensures an average light transmission of over 97 percent for clearer, more vibrant images. With a diameter of 46 mm, it is designed for durability and compatibility with various lenses, supporting photographers in landscape, portrait, and interior photography with reliable color temperature correction.