The NiSi 82mm Nano-Coated Graduated Neutral Density Filter is designed for lenses with a 82mm filter thread. It reduces the amount of light entering the lens by 4 stops is great for shooting landscapes with long exposure and deep depth of field. 4 Stop Exposure Reduction The ND filter has a density of 1.2 that reduces exposure by 4 stops. This allows use of slower shutter speeds to create motion blur or wider apertures for shallow depth of field that adds a more artistic quality to your images. Graduated ND Filter The filter’s graduated surface offers a smooth transition from ND to clear, which can be used to darken any bright or potentially over exposed parts of your photo, like the sky or clouds, to ensure correct exposure and reliable image quality. High Performance Glass The filter is made from high-quality optical glass with far greater durability than resin filters, giving it a much longer life span. The filter glass is ground, polished, and with a high-temperature coating on both sides to ensure a smooth parallel surface that delivers high quality images. Nano Coating The Nano Coating on both the sides of the filter reduces glare, reflection, and image ghosting to ensure that your photos retain the same sharpness and colour as shot without using the filter. Anti-Static and Waterproof Coating Both sides of the filter are treated with anti-static and water repellent coatings to reduce dust and also makes sure the filter easy to clean.