From Manufacturer
The Lee RF75 Graduated Neutral Density 0.9 Filter enables the shooter to adjust exposure without affecting colour balance. Exposure can be increased by 1,2 or 3 stops to suit individual situations.
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. This filter 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, the 2-stop value (ND 0.6 - the filter's clear portion allows 4x more light to pass vs. 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.
The Soft or Hard label indicates the degree of color graduation.
The Lee RF75 Rangefinder Filter Holder System offers a small, portable, flexible filter system to users of all camera formats. From small, high-end digital cameras to traditional medium and large format shooters, the RF75 is designed with a lightweight and compact design making it a perfect choice for outdoor shooting.
This system was originally targeted for small, rangefinder point-and-shoot users. However, it is an eminently viable alternative for anyone needing a compact, full-featured filter system at a reasonable price point. Film shooters as well will find this system of great benefit.
The system holds filters sized 75 x 90mm. The front assembly of the holder has been laser etched for repeatable positioning of the holder. In that way, graduated filters can be used over and over again with the same results. This is a huge benefit to rangefinder users who cannot see the effects of the filters through their viewfinder. The two filters slots on the holder have been designed to cover the widest lenses available in today's market.