Hoya Half NDX4 is a gray, neutral color half filter with an NDX4 factor. One half of the filter is transparent, while the other gradually reduces the amount of light by two stops. The transition between one and the other half of the filter is gentle, which allows you to get a soft gradient and adjust the exposure in most shooting situations. The half filter is an excellent effect filter used to eliminate strong contrasts. With it you can get a more balanced composition. It is particularly useful in landscape photography, e.g. when photographing the sunset over the sea, when there is too much difference in brightness between the sky and the earth. By using a neutral half filter you can avoid overexposure of the sky or underexposure of water.