The Tiffen Series 9 HDTV/FX 4 Filter is a gentle softening and diffusion filter specifically designed for use with high definition imaging. This filter helps to lessen the hyper sharpness that is commonly associated with HD photography and produce an image quality that is more akin to film photography. By reducing contrast and sharpness slightly, skin details appear smoother and there is an increase in shadow detail. The effects of this filter are most significant when used for video applications as opposed to still photography. The 4 density provides a noticeable amount of softening.