The Tiffen 77mm Digital HT Neutral Density Filter Kit is a collection of three filters that contain the strength of a titanium coating combined with high-end optical Water White glass. They are designed for the outdoor shooter and represent a state of-the-art advancement in filter design. The low profile design is complemented by a titanium colored filter ring that matches many of today's modern digital cameras.
Using their patented ColorCore technology, these filters takes it to the next level by adding a very high scratch-resistant surface. There is no need to worry about cleaning this filter since the coating protects the surface, thereby maintaining the high-end optical quality of the glass.
The Titanium coating consistently reflects less than 1% of the imaging light hitting the front surface of the filter while transmitting nearly 99% (i.e. High-Transmission).
Neutral Density filters have several uses and offer the possibility to achieve otherwise unachievable results. ND filters appear gray and reduce the amount of light reaching the film. They have no effect on color balance. Neutral Density filters permit you to control your depth of field by permitting you to use wider apertures. They also allow you to create some stunning "burred" images such as rippling streams, moving traffic or birds in flight.
The graduated filter in this kit offers a different photographic possibility. Often it is necessary or desirable to balance the light intensity in one part of a scene with another. This is especially true in situations where you don't have total light control, as in bright contrasty landscapes. Exposing for the foreground will produce a washed-out, over-exposed sky while exposing for the sky will leave the foreground dark and under-exposed. These filters enables cloud detail to be kept correctly exposed in the picture.
Determining which graduated neutral density filter yields ideal results for any given lighting situation takes knowledge, experience and a collection of such filters. Choose the filter strength which adjusts the lighting to stay within the exposure latitude (greatest difference between bright/dark values) which still shows details in both of the digital or film medium in use.
Speaking generally, for graduated ND filters, the 2-stop value (ND 0.6 - the filter's clear portion allows 4x more light to pass vs. the darkest portion) effectively compensates average bright sky-to-foreground situations, and the soft transition is applicable more often to a scene than the hard transition.