Hoya Variable Neutral Density II Filter The design of the Hoya Variable Density II minimizes the vignette effect often experienced when shooting on wide-angle lenses. Hoya engineers reconstructed the Variable Density frame, minimized the overall thickness and created a top frame that is one full size bigger than the original Variable Neutral Density Filter. Variable Neutral Density filters are helpful because: They save you money; buy 1 filter instead of a set of 3-4 They save time; simply rotate the filter rather than switch it out They save space; one filter takes up less room in the bag The Hoya Variable Neutral Density II Filter can be used in place of several fixed Neutral Density filters. The design of variable density filters allows you to rotate an outer frame to set the desired density the same way as a circular polarizer. A cross X pattern will occur when rotating past the minimum or maximum density range of the filter. Highlights: Thin frame design minimizes vignetting Dedicated knob for easy, precise rotation Density guide markers on frame to show density range Shoot wide open (f1.2) in daylight without overexposure Create smooth motion effects in waterfalls, rivers, waves Create motion blur of moving vehicles, trains, cars and people Features: ND3-ND400 / 1.5 stops - 9 stops Density Range Hoya Optical Glass Type Variable Light Transmission 0 Number of Multi-Coatings No Hardened Top Layer No Anti-Static Standard Profile / Aluminum Frame Construction Front Filter Threads Size: 55mm Materials: Aluminum, Optical Glass Manufacturer SKU: A-55VDY-II In The Box: Hoya 55mm Variable Neutral Density II Filter (1.5 to 9-Stop)Plastic Filter CaseLimited 1-Year Manufacturer Warranty Note: The frame construction of the Variable Density II requires taking a lens cap that is one size bigger than the filter threads of your lens. For example, a 77mm filter would require an 82mm lens cap.