RING ILLUMINATION ADAPTER

摘要

PROBLEM TO BE SOLVED: To provide a ring illumination adapter that is able to satisfactorily illuminate a close-distance subject.SOLUTION: A ring illumination adapter comprises: an incident face on which light emitted by a light source is incident; a ring-like exit face having an aperture part for allowing the light incident on the incident face to exit as ring-like illumination light; and a ring-like diffusion reflection face arranged opposite the exit face, having a slide surface and a fine projecting structure or fine recessed structure discretely arranged on the slide surface, and configured to guide the light incident on the incident face to the exit face. The exit face comprises: a ring illumination optical system having a slide face in the form of a toric surface in which the normal of the exit side face approaches the center of the aperture part as the exit face approaches the center of the aperture part; and a mount part configured to arrange the incident face of the ring illumination optical system in front of the light source, and enabling it to be attached to a photographing device such that the exit face is located in a place surrounding the optical path of the photographing optical system.