The Benro 100 x 150mm Master Series Hard-Edge Reverse-Graduated Neutral Density 0.9 Filter is compatible with filter holders that can accommodate 100mm-wide, 2mm-thick 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 up to a 3-stop reduction in light from entering a lens. This band extends vertically in both directions and tapers to a band of reduced density toward 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 with a clear area directly below allows the Benro 100 x 150mm Master Series Hard-Edge Reverse-Graduated Neutral Density 0.9 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 Benro 100 x 150mm Master Series Hard-Edge Reverse-Graduated Neutral Density 0.9 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 gradation above the 0.9 band of density is applicable to multiple regions of brightness within the sky.
Benro Master Series filters are constructed from Schott B270 glass. To prevent internal ghosting and reflections, while further enhancing clarity and color fidelity, each glass surface includes multiple layers of anti-reflection coatings. These coatings also offer greater protection to the filter substrate and help it to stay clean for longer than with uncoated filters. The nano coating associated with Benro Master Series filters provides an additional 13th layer over each side of this filter, resulting in an improved beading effect when in contact with water for greater cleaning efficiency.
