发明授权
US07019917B2 Lens barrel 失效
镜筒

Lens barrel
摘要:
A lens barrel includes an optical system including a short focal length for a wide angle of view; and an ND filter in the shape of a disc which is provided on an optical axis of the optical system. An optical density of the ND filter decreases in a direction radially outwards from a center of the ND filter.
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