Hoya 46mm 8x (0.9) Neutral Density Multi Coated Glass Filter
Neutral Density filters evenly reduce the amount of light passing thru the lens without effecting color.  Ideal for reducing bright light in large aperture situations when a narrow depth is field is needed.  Allows for slower shutter speeds when blurring or showing of movement is desired.  Allows balancing of exposure to highlight a key subject.  Lets you use higher speed films in bright light.  Hoya Neutral Density filters are available in most sizes and in three strengths:  .3 (2X) Reduces the light one f-stop.  .6 (4X) Reduces the light two f-stops. .9 (8X) Reduces the light three f-stops.