The Hoya Variable ND Filter uses two polarization layers to control the amount of light that passes through the filter and into the camera lens. At its lowest setting, the filter allows 1/3 of the light to pass through, corresponding to 1.5 stops or shutter speed values. At its maximum, the filter only allows 1/400 of the light to pass through, which corresponds to 9 stops or shutter speed values.

Once the filter is mounted on the lens, rotating the filter ring between "Min" and "Max" allows for optimal control of the amount of light entering the lens. With the Hoya variable density filter, it is possible to take pictures with fast lenses like a 50mm f/1.4 at wide open aperture in full sunlight to achieve a very shallow depth of field. Alternatively, the shutter speed can be slowed down to achieve a shutter speed of several seconds in bright sunlight. The longer shutter speed allows for motion blur effects to be created. The popular effect of flowing water appearing almost like mist can thus be achieved. Almost any moving object can create a great impression of motion in this way.

For content creators, ND filters are very helpful in adjusting shutter speeds to match frame rates while maintaining the depth of field in the footage.

The Hoya ND variable filter uses high-quality optical lenses from Hoya Corporation, the world's largest manufacturer of optical glass. It is available in diameters ranging from 52mm to 82mm. For best results, it is recommended to use a tripod when shooting with long shutter speeds.