| 摘要 |
PURPOSE:To obtain a highly accurate Bering-glare rate on any specified position of an image plane by a construction wherein a low-brightness surface of a streak- shaped body can be rotated within a plane perpendicular to the optical axis of an optical system to be measured. CONSTITUTION:When a black body 7 is rotated on an rotating shaft 7S, the low- brightness surface is rotated around a point C, and a low-brightness surface image 9 is also rotated around a point D, correspondingly. With this rotation, a background image and the low-bright surface image are alternated as seen from measuring holes 8a provided through a light screening plate 8. Therefore, a sensing body such as a photoelectric sensing element and the like which are provided at the back of the measuring hole 8a can sense a Bering-glare intensity and a background-image intensity, and a Bering-glare rate can be obtained therefrom. |
