This 5-stop, 3 x 3" Formatt Hitech HD ND Glass Filter , made with Schott-Desag B270 Crown optical glass, has been specially formulated as a result of extensive research into applications for molecular A.C.T. dyes to provide a color neutral darkening of your image without the specular effects that may occur from the particulate coatings of other neutral density and neutral density graduated filters. This can result in a cleaner image with high-resolution sensors, film stocks and scanning. HD technology has been designed to for use in cinema and video applications, taking advantage of ultra-sharp cameras and lenses.
Formatt's HD Neutral Density solid and graduated filters are available in all the popular round screw-in sizes, all the standard square sizes
All Formatt filters are finished with a unique edge frame offering maximum protection against chipping, surface scratches and enables easy handling and cleaning
With the filter description on top of the frame it also makes identification of the filter much easier especially when filters are stored in cases on location
Formatt HD Neutral Density filters have the same densities and light stops as the Kodak Wratten Standards
Formatt's Neutral Density Filters are a response to the many DPs and cinematographers who find that it is important to shoot as wide open as possible to minimize depth of field, especially with HD
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)
ND1.2 (exposure adjustment = 4 stops, reduces ISO 1/16)