The 77mm Peter McKinnon Signature Edition Variable ND 1.8 to 2.7 Filter from PolarPro is designed to mount onto lenses with 77mm front filter threads and provides an exposure reduction of 6 to 9 stops. The 1.8 to 2.7 density creates a darkening of the entire image, allowing you to photograph with a wider aperture or slower shutter speed than usually possible. The degree of density is easily controlled by rotating the front filter ring, helping you predetermine the additional exposure length required. By slowing your exposure time or increasing your aperture, you can control the depth of field and convey movement more easily. For easier, repeatable control over density settings, the front ring is visually demarcated with numbers representing the different stop values and features haptic feedback to feel a click when reaching a number, without the need to look at the ring. The ring features side knurlings for a secure grip and to further enable fast and precise positioning. To help ensure consistent exposures, the front ring is designed to prevent any rotation beyond the stop values etched on it. This filter is constructed from quartz glass for enhanced durability. To prevent internal ghosting and reflections, 16 layers of antireflective coatings offer scratch protection to the filter substrate while promoting clarity and color fidelity. The coatings associated with the 77mm Peter McKinnon Edition II variable ND 1.8 to 2.7 filter also result in an improved beading effect when in contact with water or oil, allowing for more efficient cleaning. The quartz optics are set within an aluminum alloy filter ring assembly for durability while remaining lightweight. The unique Defender 360 hybrid case/cover is included for storage and transport and acts as both a front cap when the filter is in place on a lens and as a rigid dustproof and waterproof storage case by adding the rear cover when the filter is not in use. Variable neutral density filter allows you to apply differing amounts of density from scene to scene. 1.8 to 2.7 neutral density filter darkens the image, allowing you to photograph with a longer shutter speed or wider aperture than usually possible. Providing a reduction of 6 to 9 stops, this filter allows you to control the depth of field and convey movement more easily. Offers increased flexibility to use specific ISO settings or ISO films under bright ambient light. Provides increased exposure flexibility while using cinema or video cameras within a designated film frame rate. Constructed from quartz glass for enhanced durability. Multi-coated to prevent internal ghosting and reflections while promoting clarity as well as color fidelity. Side knurlings allow the filter glass to be easily rotated. Filter ring incorporates a haptic feedback mechanism for quick adjustment, without the need to stop and look at the filter position. Front filter ring construction helps ensure that its rotation corresponds to the filter's exposure reduction range. 84mm front diameter helps reduce the likelihood of vignetting with wide-angle lenses. Slim cover for enhanced grip during filter installation and prevention of fingerprints from being left on the filter's glass surfaces. Microfiber cloth for cleaning and maintenance. Includes Defender 360 hybrid cap/case for storage and transport, featuring a waterproof and dustproof seal. PolarPro 77-6/9-VND-ED2 Specs Filter Type Variable ND Density 1.8 (6-Stop) to 2.7 (9-Stop) Circular Size 77 mm Filter Thread Front Accessory Thread / Bayonet Unthreaded Coatings Multi-Coating Filter Material Glass Ring Material Aluminum Knurling Side Packaging Info Package Weight 0.44 lb Box Dimensions (LxWxH) 4.8 x 4.7 x 1.2"