The Marumi DHG Protect Filter is a neutral filter that protects your camera lens without causing any unwanted filter effects. A standard protect filter can cause a lot of reflection and distortion to the sensor of your camera. The Marumi DHG protect filter is equipped with a special coating to overcome this by reducing the reflecting of the incoming light. The filter is made of high quality, clear glass does not effect the exposure time, allowing it to be left on the camera lens at all times.