| 摘要 |
PROBLEM TO BE SOLVED: To prevent focus variation caused by insertion and removal of an infrared cut filter and an ND filter.SOLUTION: An optical instrument includes an optical filter 238. Provided to the optical filter are a first area 1 having an infrared cut function of reducing light of an infrared range and a dimming function for light of a visible range and a second area 2 having the infrared cut function and having no dimming function. The optical filter, at the same position in an optical axis direction in which an optical path OP passing through the optical filter extends, moves with respect to the optical path to a first filter position where the first area is inserted into the optical path and to a second filter position where the second area is inserted into the optical path. |
