K&F Concept C Series variable ND filter ND2–ND32 + CPL 2-in-1 77 mm

C Series — variable ND filter 77 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 77 mm thread.

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 filter combines a polariser and a variable ND in one frame. Polarisation is set by turning the frame and the darkening from ND2 to ND32 by moving the lever, so both can be tuned independently without a second filter on the lens. Across the whole range no dark X cross appears in the image, a common flaw of cheaper variable NDs.