Neutral Density Filters
These filters are designed to reduce the amount of light coming through your camera lens without changing the color. Neutral density filters can reduce the assorted colors of light in the spectrum. White and colored light is transmitted through these filters and only the intensity of the light is affected. These filters are used with black and white and color film. If you have set your camera to its fastest shutter speed along with the smallest f/stop, but still can't take the photo without overexposing the film, you can use one of these filters to reduce the exposure further. The filters help to eliminate bright, washed out sections of a photo. Neutral density filters usually range in price from about $10 to $350. They are available in various sizes.