PURPOSE: To remove off-axis aberrations of a light, beam containing many kinds of aberration by providing a light shield film for reducing off-axis aberrations that an off-axis light beam around a main light beam emitted from one point of a body contains.

CONSTITUTION: The main light beam CR emitted from one end Q of the body passes through an entrance pupil 150, a stop 120, and then an exit pupil 140 to reach a focal plane 160. At this time, the main light, beam CR passes through an area B which is relatively high in transmissivity in a transparent area of a sequential light shield film 130 installed at the position of the exit pupil 140. Then the light beam reaches the focus 160 through a 1st lens 100, the stop 120, the entrance pupil 150, and a 2nd lens 110. Off-axis light beams (a), (b), (c), (d)... around the main light beam CR, on the other hand, have paths and transmission quantities different from those of the main light beam CR and reach the focus 160. Namely, an off-axis light beam which has large aberrations is transmitted by a small quantity through a low-transmissivity part of the sequential light shield film 130, so the degree of contribution to image formation is less than that, of the main light, beam CR. Therefore, the deterioration of an image of the body is greatly reduced by the aberrations.