77MM NDX VARIABLE ND2/ND1000 FILTER FOR. 77MM ND2/ND1000 VARIABLE NDX FILTER. 77MM NDX VARIABLE ND2/ND1000 FILTER. The 0.3 to 3.0 (ND2-ND1000) density creates a darkening of the entire image, allowing you to photograph with a wider aperture or slower shutter speed than normally required.
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