To enable slow shutter speeds to be used, especially with fast films, to record movement in subjects such as waterfalls, clouds, cars, seas, etc.
To decrease depth of field by allowing wider apertures to be used, which helps separate subjects from their background.
To allow cine and video cameras (which have fixed shutter speeds) to film subjects such as snow, sand or other bright scenes which would normally cause over-exposure.
Made of high quality optical resin with multi-Coated, effectively prevent the lens to be scratched
Anti-oil and Water resistance design
Key Features: Adapter Frame : High-density aluminum alloy 3-slots Filter Holder: Impact-resistance ABS meterial Lens Material : Optical Resin (non-glass) Solid Color Filters : ND2,ND4,ND8, ND16 Graduated Color Filters : G.ND2, G.ND4, G.ND8, G.ND16 Filter case: Durable high-density Nylon material with size 4.5" x 4.7" x 3.2" Adapter diameter: 49mm, 52mm, 55mm, 58mm, 62mm, 67mm, 72mm, 77mm, 82mm