The Hoya 58mm W12 Umber Warming Color Conversion Multi-Coated Glass Filter is a professional photography accessory designed to adjust the color temperature by warming the ambient light with a 2200 Kelvin shift, equivalent to a +120 Mired shift. This filter produces a rich dark amber tone in images and is particularly suitable for photographers using tungsten-balanced film who want to achieve natural results in daylight conditions. The W12 filter effectively counteracts the blue cast typically produced by tungsten-balanced film in daylight environments. It also performs well with tungsten-balanced film indoors under 5500 Kelvin light sources such as studio flashes or strobe lights. Compared to the W10 model, the W12 offers a stronger warming effect, delivering more neutral results with standard tungsten films. Constructed with Hoya's Multi-Coated Technology (HMC), this filter minimizes reflections and reduces stray light and ghosting while maintaining over 97 percent average light transmission. The multi-coated glass construction ensures compatibility with modern multi-coated lenses and preserves optical quality and image sharpness. With a 58mm threaded diameter, this filter fits standard lens sizes and features a durable glass construction for reliable performance in various shooting situations. The color conversion capabilities of the filter make it a versatile tool for photographers working with different film types and lighting scenarios, allowing for precise color control and consistent results across various photographic applications.