The Tiffen 4 x 5.65" Soft/FX 4 Filter can be applied to purposely reduce the appearance of blemishes and wrinkles in portraits or to apply a general soft-focus effect while maintaining overall sharpness. An array of small lenses distributed within the surface of this filter smooths fine lines and textures, which can be useful for creating a more flattering result of a subject.

This filter has a grade of 4. Grades of 1/8, 1/4, 1/2, 1, 2, 3, and 5 are also available where this filter type's effect becomes approximately twice as strong with each grade number increase. When higher grade numbers are applied, a halation effect around highlights can be created to further enhance a subject's appearance or produce a desired effect.

This filter is constructed from optical glass for clarity as well as color fidelity and is compatible with filter holders that can accommodate 4mm-thick, 4 x 5.65" rectangular filters. It is made using ColorCore technology, a process that involves laminating the filter substrate between two pieces of optical glass and grinding flat to a tolerance of 1/10,000th of an inch.