Cokin Z-PRO 152 Gray Neutral Density 0.3 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.
Determining which neutral density filter yields ideal results for any given lighting situation takes knowledge, experience and a collection of such filters. Speaking generally, the 2-stop value (ND 0.6) effectively compensates average situations.
Z-PRO Filters are made of CR39 Resin which is a reputable lightweight and unbreakable optical material also used for ophthalmic glasses. The Z-PRO Series is recommended for focal lengths of 20mm onwards (in the 35mm format).
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 to 1/2)
- ND.6 (exposure adjustment = 2 stops, reduces ISO to 1/4)
- ND.9 (exposure adjustment = 3 stops, reduces ISO to 1/8)