Variable 0.3 - 1.5 Filter Factor, Reduce Exposure by 1.0 to 5.0 Stops, Darkens Entire Image, Allows Reduced Shutter Speed, Allows Wider Aperture, Optical Glass Construction, Multicoating, Resistance Coating, Includes 49mm Magnetic Adapter Ring. This 49mm Nano X-Pro Magnetic ND2-32 Variable Neutral Density Filter from K&F Concept is an adjustable neutral density filter with a 1-5 stop exposure range that can easily control the amount of light entering the lens for finer image control. The filter density is easily changed by rotating the filter ring and the advanced optical design prevents the X pattern found on lower-quality filters from appearing on the image.This filter darkens the entire image area evenly allowing a photograph to be made with a slower shutter speed or wider aperture than normally required. Slowing the shutter speed increases the exposure making it possible to increase image blur to emphasize motion as when shooting flowing water. Alternately when increasing the aperture provides finer control over depth of field useful when trying to isolate the subject or increase bokeh. This adjustable filter is especially useful when shooting landscapes and in very bright light conditions and can be used for both still and video imaging. Adjusting filter density also makes it possible to control frame rate when shooting video.This optical glass filter features a 28-layer nano-coating to reduce potential flare and glare and for optimal resolution and color transmission. It also provides a resistance coating that repels oil and water plus minor scratches and abrasions making suitable for use on location even in harsh environments. This durable aluminum-magnesium alloy filter ring includes magnetic adapter ring that fits lenses with 49mm filter threads allowing it to be attached and exchanged in seconds.