The 100x150mmNano IR Soft Graduated Neutral Density Filter - ND8 (0.9) - 3 Stop is a rectangular filter that helps to darken specific areas of an image, such as bright skies while allowing for a normal, unaffected exposure in the other regions of the image. The filter is densest at the edge and tapers to clear by the middle, with a soft-edged line of transition between the dense and clear areas. A neutral density filter with a soft-edged line of transition is particularly useful for images that feature trees, buildings, mountains and other elements that protrude into high into the skyline. NiSi GND filters do not affect the coloration of the image, offer a true to life color and are made from high-quality optical glass (not resin) with nano coating to prevent losing any single bit of detail. By using neutral density filter the camera is vulnerable to infrared light which will cast the unwanted red color to the photos when shooting at a small aperture. NiSi GND filters have an infrared protection coating layer to eliminate the infrared light through the lens to bring back the natural true to life color. The NiSi 100mm filter system is great for cameras with lenses that have a standard filter thread from 49 mm to 95mm. This 100mmx150mm filter is compatiblewith the NiSi 100mm filter system.