K&F Concept Nano-X 2-in-1 Variable ND4–ND64 and CPL Filter, 37 mm

Nano-X — variable ND filter 37 mm, changes the amount of light steplessly as you turn it.

• 28 anti-reflective layers
• Two filters in one: variable ND4–ND64 (2–6 stops) and CPL polarisation
• No X-cross effect, the range is set with a lever marked ND4–ND64
• Screws onto a lens with a 37 mm thread.

Variable ND filter

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.

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.