The 85mm Neutral Density Filter Kit from Hitech is designed for the Cokin P system. The three filters in this kit offer the possibility to achieve otherwise unachievable results. They enable the shooter to adjust exposure without affecting color balance. An ND filter appears gray and reduces the amount of light reaching either the sensor of a digital camera or the film plane of a traditional film camera.
A Neutral Density filter is also used to create some unusual special effects such as capturing the "blur" of the rippling water of a waterfall or the swirling effect of city traffic. Since it allows the use of slower shutter speeds in bright light, it becomes possible to create these special effects that would normally not be possible to capture without the filter. And since it can also help to control your depth of field, it permits you to shoot at wider apertures. Ultimately, its value is in helping to prevent bright, overly washed out images shot in bright light.
The Hitech filter system is made by Formatt - an English company that is renowned for its high manufacturing standards and consistency of quality. Their CR39 resin is manufactured in large sheets that are oven cured. Their exclusive Absorbing Cell Technology absorbs color as opposed to other filters that are coated. Once cured, they are sliced up to create individual filters. In this way, maximum consistency is maintained from filter to filter. This becomes crucial when you wish to change filters either mid shoot or from day to day.
Neutral Density Filters Have Four Main Uses
To enable slow shutter speeds to be used, especially with high speed ISOs, 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 situation
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
Absorbing Cell Technology
The secret to Formatt's consistency in filter design lies in its unique "Absorbing Cell Technology" (A.C.T.); this unique process allows color correct dyes to be applied to optically pure, wafer thin absorbing cells and offers a controllability that ensures the smoothest grad lines and consistent color across the whole filter surface
Hitch filters are manufactured to exacting standards and can be counted on to be consistent filter to filter which means you can change filters mid shot or from day-to-day and still maintain the same exposure
Hitech filters are made by Formatt, a company with three generations of professional filter-making experience produces every filter to the highest technical standards. The finest materials, together with state of-the-art production technology have resulted in a standard of optical excellence unmatched anywhere else