K&F Concept Nano-X variable ND filter ND2–ND32 + CPL 2-in-1 55 mm

Nano-X variable ND filter ND2–ND32 + 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.

• Screws onto a lens with a 55 mm thread.
• The surface repels water and grease and resists scratches

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 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.

The filter combines two pieces of glass that otherwise have to be stacked: a polariser and a variable ND from ND2 to ND32. That removes one element from the light path and with it the vignetting risk of two stacked filters. The frame carries five marks from ND2 to ND32, so the strength can be set blind, and the knurled rim grips even in gloves.