K&F Concept 77mm Nano-X Variable/Fader ND Filter, ND32-ND512, W/O Black

Nano-X — variable ND filter 77 mm, changes the amount of light steplessly as you turn it.

• Screws onto a lens with a 77 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.

A strong range for long exposures in broad daylight — water melts into mist, clouds stretch into streaks and people vanish from the square. For everyday filming it is needlessly dark, but for this the alternative is stacking fixed filters.