The Tiffen Double Fog 1 Filter
simulates the effects of natural fog or mist by creating a soft glow
around highlights and lowering the overall contrast of the scene. When
compared to the standard Fog filter, this filter places greater emphasis
on lowering the contrast while maintaining sharpness and minimizing the
effects of flare. The 1 density provides less fog effect that the 2 but more than 1/2.
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.