Reverse graduated ND filter with inverted density curve – maximum darkening at image bottom, less at top. For sunsets with bright sun at horizon and dark foreground.
Technical Details
The filter is made of optical glass with gradually vapor-deposited metal oxide layers. Standard dimensions include 100x150mm and 150x170mm for matte box systems. The transition zones range from 25-40mm with soft or hard gradients. Lee Filters produces Reverse ND filters with a maximum density of 0.6/0.9/1.2, while Formatt-Hitech offers up to 1.5. Spectral transmission remains consistently neutral over 400-700nm with less than 1% color shift. Magnetic filter frames allow precise positioning during shooting.
History & Development
The Reverse Grad ND was developed in 2009 by Lee Filters in collaboration with landscape photographers for extreme backlight situations. Cinematographer Roger Deakins popularized its use from 2011 onwards for exterior shots with significant brightness differences. In 2015, Formatt-Hitech introduced harder transitions, followed by magnetic systems from NiSi in 2018. Modern versions utilize ion beam sputtering for more uniform coatings and longer durability.
Practical Application in Film
Roger Deakins used Reverse ND filters in "Blade Runner 2049" (2017) for sunsets in Las Vegas to capture the orange-red sun and dark city ruins in detail. In "1917" (2019), the filter enabled simultaneous exposure of trenches and dramatic sky at dawn. The filter is primarily used during Golden Hour and Blue Hour when the sun is near the horizon. Workflow: Position the maximum density on foreground elements, the horizon in the weakest zone, and moderate sky darkening in the upper image area.
Comparison & Alternatives
It differs from the standard Graduated ND by its inverse density curve – while the latter gradually decreases from the top edge to the middle, the Reverse ND concentrates maximum darkening in the lower image area. Hard-edge versions are suitable for defined horizon lines, soft-edge for irregular contours. Digital blending of multiple exposures offers more flexible post-processing but requires a tripod and static subjects. Variable ND filters can reduce brightness differences but cannot selectively address different image zones.