The Tiffen 6.6 x 6.6" Fog 2 Filter simulates the effects of natural fog or mist by creating a soft glow around highlights and lowering the overall contrast of the scene. There can also be a softening effect due to how the light interacts with the subject matter. The 2 density provides a greater amount of fog effect than the 1, but less than the 3, and requires no exposure compensation.
Tiffen filters are 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 6.6 x 6.6" / 167.6 x 167.6mm.