K&F Concept Nano-X True Color variable ND filter ND2–ND32 49 mm

Nano-X True Color variable ND filter ND2–ND32 49 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 49 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.

Ordinary variable ND filters pull the image towards yellow-green and the colour has to be fixed afterwards. This glass is built for faithful rendering: snow stays white and a sunset keeps the hue it actually had. End stops limit the range to ND2 through ND32. The filter cannot be turned past the end of the scale, which is where variable NDs produce the dark cross over the image.