entrance pupil


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entrance pupil

[′en·trəns ‚pyü·pəl]
(optics)
The image of the aperture stop of an optical system formed in the object space by rays emanating from a point on the optical axis in the image space.
References in periodicals archive ?
The exposure light from the illumination system is converted into a rectangular shape that illuminates only a portion of the reticle and images it through the entrance pupil of the lens.