The Hitech 165mm Master Neutral Density Filter Kit (Hard Edge) contains a wide range of 6 neutral density filters, including both hard-edged graduated and solid.
The solid ND filters included are 0.3, 0.6, and 0.9 densities, offering exposure reduction of 1, 2, and 3 stops respectively. An ND filter creates a darkening of the entire image, allowing you to photograph with a wider aperture or slower shutter speed than normally required. By slowing your exposure time or increasing your aperture, you are able to control depth of field and convey movement more easily. These filters measure 6.5 x 6.5" / 165 x 165mm and are constructed from specially dyed CR-39 resin.
The ND Grad filters included are 0.3, 0.6, and 0.9 densities, offering exposure reduction of 1, 2, and 3 stops respectively. A graduated ND filter has density on half of the filter surface, helping to darken skies and other bright areas of the image. The filter is most dense at the edge and abruptly tapers to clear by the middle of the filter. The filters measure 6.5 x 7.9" / 165 x 200mm and are constructed from specially dyed CR-39 resin.