The 4 x 5.65" Mitchell Diffusion Filter "B" from Pancro is a softening diffusion filter made from a single piece of optical-select glass. It is often used for facial close-ups to soften undesirable features such as freckles, blemishes and wrinkles by refracting a portion of light as it passes through the filter. It also creates a romantic ambiance by softening colors and cutting sharpness. Whether softening facial features and colors, or cutting sharpness, the final effect on screen is subtle and unobtrusive, the use of a filter is undetected. Filter density starts at "A" where it is the least dense, and increases incrementally to "E".