Photometric device

A photometric device (1) is provided with a variable optical attenuator (4). The variable optical attenuator (4) includes a plurality of optical attenuation filters and a driving device (5). The plurality of light attenuation filters each include an interference multilayer film and a transparent substrate. The combination of any two of the plurality of light attenuation filters is set as a first light attenuation filter (light attenuation filter (10)) and a second light attenuation filter (light attenuation filter (20)). A first optical path length of a first transparent substrate (transparent substrate (11)) of the first light attenuation filter is different from a second optical path length of a second transparent substrate (transparent substrate (21)) of the second light attenuation filter. 测光装置(1)具备可变光衰减器(4)。可变光衰减器(4)包括多个光衰减滤光器和驱动装置(5)。多个光衰减滤光器各自包括干扰多层膜和透明基板。将多个光衰减滤光器中的任意两个的组合设为第一光衰减滤光器(光衰减滤光器(10))和第二光衰减滤光器(光衰减滤光器(20))。第一光衰减滤光器的第一透明基板(透明基板(11))的第一光路长度与第二光衰减滤光器的第二透明基板(透明基板(21))的第二光路长度不同。