K&F 72MM, True Color Variable ND2~ND400, ultra-thin adjustable filter

C Series — variable ND filter 72 mm, changes the amount of light steplessly as you turn it.

• Screws onto a lens with a 72 mm thread.

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.

Nine stops in one piece of glass cover everything from a mild cut in light to long exposures in broad daylight — water turns to mist and clouds stretch into streaks. The range is set by turning the front ring, steplessly.

Ordinary variable NDs pull the picture towards yellow-green and the colours then have to be straightened out in post. The True Color coating suppresses that shift, so snow stays white and water keeps the tone it actually had.