This Nano Hard-Edge Reverse-Graduated IRND 0.9 to 0.15 Filter from NiSi is compatible with filter holders that can accommodate 2mm-thick, 180 x 210mm rectangular filters. It can be applied to darken bright skies, specifically during a sunrise or sunset, while allowing for a normal, unaffected exposure in the other regions of the image.

This filter achieves its effect with a 0.9 band of density across its center region that provides a 3-stop reduction in light from entering a lens. This band extends approximately 4mm in both vertical directions which tapers to a 0.15 density that provides a 0.5-stop reduction in light at the edge above it. Directly below the 0.9 band of density, it tapers to clear, with a hard-edged line of transition before the clear area.

The placement of a 0.9 band of density that tapers to a density of 0.15 above it with a clear area directly below, allows the NiSi 180 x 210mm Nano Reverse-Graduated IRND 0.9 to 0.15 Filter to match the positioning of the sun when it is at, or immediately above the horizon. In such instances, the sun can appear closer to the center of an image as opposed to the upper edge, and an increase in brightness is created that is more prominent on both sides of the sun than above it. This pattern of brightness corresponds to the density pattern on the NiSi 180 x 210mm Nano Hard-Edge Reverse-Graduated IRND 0.9 to 0.15 Filter. The hard-edged line of transition in this reverse, graduated neutral density filter is useful for hard transitions between the sky and land, while the 3-stop to 0.5-stop gradation is applicable to multiple regions of brightness within the sky.

• Compatible with filter holders that can accommodate 2mm-thick, 180 x 210mm rectangular filters
• Effectively darkens bright skies, specifically during a sunrise or sunset, while allowing for a normal, unaffected exposure in the other regions of the image
• 3-stop band of density that tapers to a 0.5-stop density at the edge above it while directly above a clear area creates a neutral density pattern that matches the positioning of the sun when it is at, or immediately above the horizon
• 3-stop band of density extends approximately 4mm in both vertical directions
• Density pattern corresponds to the brightness pattern of the sun when it appears at or is closer to the horizon as opposed to a higher angle, which creates an increase in brightness that is more prominent on both sides of the sun than above it
• Hard-edged line of transition between the 3-stop band of density and the clear area below it is useful for hard transitions between the sky and land
• 3-stop to 0.5-stop gradation is applicable to multiple regions of brightness within the sky
• Filter does not affect the overall coloration of the image
• Each surface includes one layer of NiSi Optical Nano Coating that attenuates infrared light as well as visible wavelengths, to maintain color neutrality and suppress color casts due to increased exposure times
• Nano coating provides an improved beading effect with water or oil for more efficient cleaning
• Constructed from optical glass for clarity
• Leatherette pouch included for storage and transport