The Lee RF75 Basic Filter Set contains three (3) valuable filters for those who enjoy shooting outside.
Graduated Neutral Density
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.
Standard ND Filter
Unlike the graduated ND filter, this filter is neutral density from top to bottom and allows the use of fast film in bright situations since it reduces the amount of light reaching the film.
This filter controls the bluish coloration that affects daylight film. It can also remove excessive blue from the effects of electronic flash.
It's Autumn. The clouds are low hanging and the sky is "patchy blue". You've gone for a ride upstate to the mountains and the light in open shade is bluish. A photo taken of your girlfriend with daylight balanced film leaning against the side of a barn will yield bluish tones that she might not find particularly flattering.
An 81B filter will replace even more yellow than an 81A and bring her skin tones back to a more appealing level. An 81B can also be used with electronic flash to reduce the amount of "blue" generated by the flash. The 81 series (81A, B, C, D and EF) allows you to choose how much warmth you wish to replace in the image.
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.
Note: RF75 Filter Holder sold separately
Neutral Density Filters Have Four Main Uses
- To enable slow shutter speeds to be used, especially with high speed films, to record movement in subjects such as waterfalls, clouds, or cars
- To decrease depth of field by allowing wider apertures to be used, which helps separate subjects from their background
- To decrease the effective ISO of high speed film (above ISO 400) and allow it to be used outdoors in bright situations
- To allow cine and video cameras (which have fixed shutter speeds) to film subjects such as snow, sand or other bright scenes which could cause overexposure
Neutral Density Factors
- ND.3 (exposure adjustment = 1 stop, reduces ISO 1/2)
- ND.6 (exposure adjustment = 2 stops, reduces ISO 1/4)
- ND.9 (exposure adjustment = 3 stops, reduces ISO 1/8)
- 81B decreases color temperature from 3500 - 3200K