Fotodiox 145mm Multi-Coated Neutral Density 1000 10-Stop Filter for WonderPana 145 and 66 Systems Premium grade optical glass filter; high quality, double threaded, ND1000 filter Premium grade anodized aluminum ring; 145mm x 1mm standard filter thread; filter ring is 7mm thick Enables slow shutter speeds to be used, allowing film to record movement in subjects such as waterfalls, clouds, or cars. Decrease depth of field by allowing wider apertures to be used, in turn helping to separate subjects from their background. Decrease the effective ISO of high-speed film and allow it to be used outdoors in bright situations. Allows video cameras (which have fixed shutter speeds) to film subjects such as snow, sand or other bright scenes that can cause overexposure. 24-Month Manufacturer Warranty