This 67-82mm RevoRing Variable ND & Circular Polarizer Filter from H&H Filters combines a variable neutral density filter with a 1.5 to 10-stop increase in exposure, paired with a circular polarizer. Combining these functions results in a filter well suited to landscape photography and more. The RevoRing is a unique adapter ring with unique self-retracting blade technology with threaded ends to secure to the front of any lens with a filter thread size of 67-82mm. Each threaded blade has been designed to overlap, removing any possibility of light leaks.
Increasing neutral density allows longer exposure times, increasing blur and emphasizing movement. It can also be used for finer aperture control over the depth of field, making it easier to isolate the subject from the background by increasing bokeh. The circular polarizer component of the filter helps eliminate reflections and glare by filtering out light that has become polarized due to reflection from nonmetallic surfaces. It also reduces haze in landscapes and increases the saturation of skies and foliage.