K&F Concept Nano-X magnetic variable ND filter ND2–ND32 49 mm

Nano-X Magnetic — variable ND filter 49 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.

• 28 anti-reflective layers
• Magnetic mount — on and off in a second
• The surface repels water and grease and resists scratches

Magnetic mount

The filter goes on magnetically — a magnetic adapter ring screws onto the lens and the filter holds itself on. A swap takes a second and nothing has to be screwed.

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 ND2 to ND32 range is the one used most in video — it keeps the shutter at 1/50 from shade to hard sunlight. The end stops prevent turning into the position where cheap variable NDs produce the dark cross across the frame.