Fr.: pupille d'entrée
In an → optical system, the image of the → aperture stop formed in → object space. See also → exit pupil.
Fr.: pupille de sortie
In an → optical system, the → image of the → aperture stop formed by the elements following it. See also → entrance pupil.
1) In the → eye, the apparently black opening in the center of the
→ iris that permits light to pass and be focused on the
From M.E. pupille, from O.Fr. pupille, from L. pupilla, originally "little girl-doll," diminutive of pupa "girl, doll" (Fr. poupée), so called from the tiny image one sees of himself reflected in the eye of another.
Mardomak "little man," the allusion being to the tiny image of himself reflected in the eye of another, from mardom "man, human being, mankind, people;" → people, + diminutive suffix -ak.
Fr.: masquage de pupille
A method for reaching the → diffraction-limited → angular resolution of a monolithic telescope by using an → interferometric technique. A mask with several small openings is placed in the telescope pupil plane or in a conjugated plane so as to only pass light from selected regions, thus transforming the telescope into an array of small subapertures without redundancy. When the light from each of these separate subapertures is combined, → interference fringes are formed which encode information on the spatial structure of the source (Haniff et al. 1987, Nature 328, 694). Coupled with a novel technique which filters the → atmospheric turbulence through fibers, pupil masking allows reaching a high dynamic range (Perrin et al. 2006, MNRAS 373, 747), which is necessary for detecting very faint objects, such as → exoplanets, adjacent to bright stars.