K&F CONCEPT Variable ND2-ND400 ND Filter 37-82mm Adjustable Neutral Density Camera Lens Filter With Blue Anti-Scratch Coating Product Description: Slim Adjustable ND Filter Feature: -- Reduces the amount of light reaching the film without affecting the color. --Applies slow shutter speed under strong sunlight exposure. --Glass mounted with high pressure press technology. -- Made of high quality optical glass by K&F Concept technology. --Wider outer optic to help reduce vignetting at wide angles. --Extinction paint seiko manufacturing,To achieve the testing sights on military standard. ND Filter Use Effect: --Neutral density can be adjusted from ND2 to ND400, Reduces the amount of light reaching the film without affecting the color. --Have Control of Any Lighting Environment. --Allows wider apertures, effectively decreasing depth of field. --Suitable for dynamic screen, waterfalls, streams, waves, etc. Multi-Resistance Coated --The K&F Polarizers Filter Multi Resistance Coating (MRC) helping repel water, dust & grease, while also preventing ghosting. --All these fantastic attributes are essential for working effectively outdoors. Our proprietary MRC coating is structurally harder than the glass itself and the reduced reflections improve the efficiency since less light is lost. NOTE: 1.Please verify your cameras's lens thread size before ordering.This number is always preceded by a "Ø"(diameter) symbol. 2.When using the ND filter to the maximum(ND400) or bigger degree density, it will appear "X" spot or a blur in the picture,this is a normal phenomenon. (Suggestion:lower down the density value gradually and reduce the aperture, until the facula disappeared)