| 摘要 |
PROBLEM TO BE SOLVED: To provide a ND filter allowing reproductive, easily gradual, or continuous alteration of optical density in a single ND filter, and a manufacturing method thereof.SOLUTION: The ND filter of the present invention is a ND filter formed from a composition (X) containing a thermoplastic (A) having a light transmittance of 85% or more at a wavelength of 380 to 780 nm with a thickness of 1 mm; a metal oxide and/or metal nitride (B) having an absorption in a visible light region with a primary particle diameter of 10 to 80 nm; and an infrared absorbent (C), where for the average value T(ave)of the light transmittance at a wavelength of 400 to 700 nm, the minimum value T(min)and the maximum value T(max)of the light transmittance satisfy the following formulas (1) and (2): 0.92×T(ave)≤T(min)(1);1.08×T(ave)≥T(max)(2). |
