The Tiffen Fog Filter is a great special effect filter to have on hand to enhance your photography. This filter mimics the effect of natural fog and produces a warm romantic tone by creating a soft glow and flare. The fog filter comes in a variety of strengths, the lower number indicates a lighter grades which takes the edge off excess contrast and sharpness. The higher numbers indicate heavier grades which create unnatural effects, as in a fantasy sequence or a dreamlike aura of mystery.