A lens device comprises: an image-formation optical system that converges an incident luminous flux at an imaging element, to form an image; a diaphragm mechanism provided in the image-formation optical system; and a filter section that is provided on a subject side of the imaging element and through which the luminous flux incident on the image-formation optical system travels, wherein the filter section comprises: an infrared-ray cutoff filter; and a neutral density filter, and wherein the lens device further comprises a filter switching mechanism that places the infrared-ray cutoff filter and the neutral density filter in a range through which the luminous flux travels at the time of photographing of a high-luminance subject.