The 100 x 150mm K-Series Reverse-Graduated Neutral Density 0.9 Filter from H&Y Filters 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 above its center region that provides up to a 3-stop reduction in light from entering a lens. This band extends in both vertical directions which tapers to approximately a 0.3 density and a 1-stop reduction in light at the edge above it. Directly below the 0.9 band of density, it tapers to clear, with a soft-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 100 x 150mm K-Series 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 which is more prominent on both sides of the sun than above it. This pattern of brightness corresponds to the density pattern on the 100 x 150mm K-Series Reverse-Graduated Neutral Density 0.9 Filter. The soft-edged line of transition in this reverse-graduated neutral density filter is useful for images that do not have a strongly defined transition between the sky and the foreground, while the 3-stop to approximately 1-stop gradation is applicable to multiple regions of brightness within the sky.

The 100 x 150mm K-Series Reverse-Graduated Neutral Density 0.9 Filter is pre-installed with an H&Y Filters 100 x 150mm Quick Release Magnetic Filter Frame for use with an H&Y Filters 100mm K-Series Filter Holder. When combined with a 100mm K-Series Filter Holder that is configured with a pair of magnetic filter slots, filters each with a Quick Release Magnetic Filter Frame can be magnetically stacked in front of a camera lens instead of inserted only within a specific number of filter holder slots, allowing the user to determine the number of filters to be applied, all of which can be quickly installed, repositioned, or switched with a different filter needed for other subjects or changing lighting conditions.

While in use, front-facing center finder rulers on the side sections of this Quick Release Magnetic Filter Frame help enable precise positioning of the 100 x 150mm reverse-graduated neutral density filter, relative to another filter it is stacked on. This can further complement the use of the 100 x 150mm reverse-graduated neutral density filter whose effect can be adjusted to better suit changing lighting conditions or creative demands by moving it up or down. The Quick Release Magnetic Filter Frame also serves to reinforce the edges of the 100 x 150mm reverse-graduated neutral density filter, enhancing that filter's rigidity and promoting sharp results by helping to ensure that the filter remains flat. A filter pouch for storage and transport and a microfiber cleaning cloth for filter maintenance, are also provided.