This Helix Variable Neutral Density Filter from PolarPro is designed for the Helix magnetic filter system and provides an exposure reduction of 2 to 5 stops. It darkens the entire image area, allowing a wider aperture or slower shutter speed than is usually possible. Increasing neutral density offers finer control in available shutter speeds or aperture settings for both still and video applications. Using a longer shutter speed makes it possible to increase blur to convey a sense of movement or to dial in a video camera frame rate. Increased density also makes it possible to shoot using wider lens apertures, helping to isolate a subject from the background and increasing bokeh. This filter provides 2-, 3-, 4-, and 5-stop density increase. The front ring features a numbered scale of the stop values, and it also features haptic feedback to feel a click when reaching a number without looking at the ring. The ring features side knurling for a secure grip and to further enable fast and precise positioning.
Unlike other magnetic filter systems, the Helix system provides a completely secure connection using a magnetic connection plus a quarter-turn locking mechanism, making it lightning-fast to install and remove filters. This advanced locking system ensures filters stay locked in position, even during the most demanding shooting situations.