Neutral Density filters reduce the amount of light passing through the camera lens without changing the color of the scene. Especially useful in bright light conditions to help prevent overexposure. Also allows proper exposure at a wider lens opening for reduced depth-of-field to highlight a key subject by making the foreground and/or background out of focus. Neutral Density filters eliminate overly bright, washed-out images, balance exposure, control depth-of-field and allow slower shutter speeds to produce blurred motion effects.