K&F Concept Nano-X variable ND filter ND4–ND64 + CPL 2-in-1 55 mm

Nano-X variable ND filter ND4–ND64 + CPL 2-in-1 55 mm, changes the amount of light steplessly as you turn it. It is a favourite for filming on bright days, as it lets you keep a cinematic shutter and a wide aperture without blown highlights or swapping filters between takes.

• 28 anti-reflective layers, reflectance 0.2 %
• Screws onto a lens with a 55 mm thread.
• Water-, grease- and scratch-resistant surface

Light under control with one turn

A variable ND replaces a whole set of fixed grey filters — turning the front ring changes how much light gets through, steplessly. While filming the shutter stays at 1/50 s even as the sun goes behind a cloud and comes back, with no need to stop the take or swap a filter.

The glass carries 28 anti-reflective layers and reflects only 0.2 % of the light, so no ghosting or veiling appears against the light. The surface repels water and grease, so drops run off and fingerprints wipe away without smears; the coating also stands up to cleaning in the field. Two functions in one piece of glass: the variable ND cuts two to six stops and the polarising layer also takes the glare off water and glass. One filter sits on the lens instead of two stacked, so there are no extra reflective surfaces and no added risk of dark corners.