The Tiffen 4 x 4" Black Glimmer Digital Diffusion/FX 4 Filter is a softening and diffusion filter specifically meant to appear invisible, as if no filtration is being applied. Compared to other diffusion filters, this filter offers virtually no flare or loss of contrast for more subtle applications. It helps to lessen facial blemishes, wrinkles, and gently smooth textured backgrounds while maintaining sharp focus. In addition to the softening qualities of this filter, an increased glow and a smooth transition between highlights and shadows are also provided. The 4 density provides more softening than the 3, but less than the 5.
This filter is constructed from Water White glass and is made using ColorCore technology, a process that involves laminating the filter substrate between 2 pieces of optical glass and grinding flat to a tolerance of 1/10,000th of an inch. This filter measures 4 x 4" / 101.6 x 101.6mm.