A natural mist causes lights to glow and flare. Contrast is lower, and sharpness may be affected as well. Mist filters mimic the effect of atomized water droplets in the air. These filters can take the edge off excess contrast and sharpness, and are commonly used for portaits.
This filter is a Mist Clear with a clear spot. It measures 4 x 6" (100 x 150mm) x 2mm thick. The 6" length allows for adjustment of the filter within the holder.