Genustech Eclipse ND Fader 77mm Variable ND Filter

The Eclipse ND Fader replaces a set of fixed ND filters with one ring: rotate it and the density sweeps across roughly 2 to 8 stops, so exposure can be pulled down for a wide aperture or a slow shutter without swapping glass mid-shoot. Genustech builds the front element wider than the 77mm thread it fits, which keeps the filter from vignetting on wide-angle lenses the way a same-size flat ND often does.

A laser-treated optical coating is what keeps the image color-neutral through the adjustment range rather than shifting warm or cool as the filter is rotated, and the housing is cut thin to leave clearance for a lens hood. Genustech's own safety note applies here as with any ND fader: never use it as a viewing filter for looking directly at the sun.