The Hoya Variable Density filter uses two polarizing layers to control the amount of light that passes through the filter and into the camera lens. After the filter is mounted on the lens, turning the filter ring between "Min"� and "Max"� can greatly control the amount of light entering the lens. With the Hoya Variable Density filter, it's possible to shoot with fast lenses in full sun for a very shallow depth of field or to slow down the shutter speed to where the shutter can be open for several seconds in full sunlight.The Hoya Variable Density filter uses high-quality optical glass from Hoya Corporation, the world's largest optical glass manufacturer and is available in sizes 52mm to 82mm. For best results, it's recommended to use a tripod when photographing with slow shutter speeds. This filter makes easy to adjust the brightness of a scene and have more control over the exposure settings of the camera. The filter reduces light transmittence by approximately 1/3 - 1/400, This allows a much greater range of shutter speed and aperture values to be set according to the desired effect.
