B + W 55mm #101 0.3 (2x) 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.
• B&W Neutral Density filters are available in the following strengths:
• .3 (2X) #101 Reduces the light one f-stop.
• .6 (4X) #102 Reduces the light two f-stops.
• .9 (8X) #103 Reduces the light three f-stops.
• 1.8 (64X) #106 Reduces the light six f-stops
• 3.0 (1,000X) #110 (ten f-stops) & 4.0 (10,000X) #113 (seventeen f-stops) are for astronomical and sun studies.