The NiSi 4 x 4" Nano Soft-Edge Graduated IRND 0.9 Filter is a square 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. Neutral density filters do not affect the coloration of the image and this filter provides up to a 3-stop reduction in light from entering the lens.
The design of this filter has been optimized for use with digital sensors and to promote nearly flat attenuation of visible and infrared light. Due to imaging sensors' greater susceptibility to infrared light, compared to traditional film, color casts can occur when photographing darker subjects that require increased exposure times. To provide a high level of neutrality across the visible and infrared spectrums in order to eliminate color casts and ensure cleaner, truer blacks when using the NiSi 4 x 4" Nano Soft-Edge Graduated IRND 0.9 Filter, one layer of NiSi Optical Nano Coating is applied to each of this filter's surfaces.
This NiSi 4 x 4" Nano Soft-Edge Graduated IRND 0.9 Filter is constructed from optical glass for clarity as well as color fidelity, and measures 4mm thick.