| 摘要 |
<p>PROBLEM TO BE SOLVED: To solve the problem that when the wavelength of a near-infrared projector changes in the case of photographing a near-infrared region by moving a flange back position, image blur occurs in the case of switching photography from a visible region to the near-infrared region.SOLUTION: A lens device includes: a focus optical system; a flange back optical system; an extender optical system; focus driving means for driving the focus optical system; flange back driving means for driving the flange back optical system; focus evaluation means for evaluating the focusing state of a photographing object; focus control means for driving the focus optical system to focus on the photographing object on the basis of evaluation information from the focus evaluation means; and photography selection means for selecting a photographing wavelength region between a visible region and a near-infrared region. When selection is switched from visible photography to the near-infrared photography by the photography selection means, or the extender optical system is changed in the near-infrared photographing state, the focus control means drives the flange back optical system to focus on the photographing object on the basis of the evaluation information from the focus evaluation means.</p> |
