METHOD FOR MANUFACTURING ND FILTER, AND LIGHT QUANTITY DIAPHRAGMING DEVICE AND CAMERA COMPRISING THIS ND FILTER

摘要

PROBLEM TO BE SOLVED: To provide a method for manufacturing an ND filter of which the spectrum characteristic has a flat gradation density distribution at each light density, and a light quantity diaphragming device and a camera which are provided with this ND filter and capable of coping with high-quality imaging.;SOLUTION: When manufacturing the ND filter by forming at least two or more kinds of films on a substrate, the method is comprised of a process for forming films by forming the gradation density distribution on them except on the top surface layer by using a variable mask 19 arranged between an evaporation source 16 and a film-forming substrate 3, and a process for forming the film of the top surface layer with constant thickness by using the mask.;COPYRIGHT: (C)2004,JPO&NCIPI