The 3-stop Tiffen 138mm Combination Light Balancing 81EF/ND 0.9 Filter combines the effects of an 81EF light balancing filter with a neutral density filter. An 81EF filter, the strongest in the 81 series, will more than replace the yellow missing from the image and place all skin tones on a distinctly "warmish" level. Neutral density filters appear gray and reduce the amount of light entering the lens. They have no effect on color balance and are very useful when you want to shoot high-speed film outdoors on a very bright day.
Tiffen's ColorCore glass is produced through a process that entails permanently laminating the filter material in between two pieces of optical glass that are ground flat to tolerances of 1/10,000th of an inch, then mounted in precision aluminum rings. This process makes for greater accuracy of color as opposed to glass that is simply dyed and become subject to deviation during the dye process.
- Good for general scenics when the photographer wishes to remove the bluish cast from open shade or just add warmth to the photograph, with an 81EF having the greatest effect
81 Series Conversion Factors - 81 decreases color temperature from 3300 to 3200K
- 81A decreases color temperature from 3400 to 3200K
- 81B decreases color temperature from 3500 to 3200K
- 81C decreases color temperature from 3600 to 3200K
- 81D decreases color temperature from 3700 to 3200K
- 81EF decreases color temperature from 3900 to 3200K
- Enable slow shutter speeds to be used, especially with high speed films, to record movement in subjects such as waterfalls, clouds, or cars
- Decrease depth of field by allowing wider apertures to be used, which helps separate subjects from their backgrounds
- Allow cine and video cameras (which have fixed shutter speeds) to film subjects such as snow, sand, or other bright scenes that could cause overexposure
Neutral Density Factors - ND 0.3 (exposure adjustment = 1 stop, reduces ISO 1/2)
- ND 0.6 (exposure adjustment = 2 stops, reduces ISO 1/4)
- ND 0.9 (exposure adjustment = 3 stops, reduces ISO 1/8)