a. 用暗箱的

Scioptic \Sci*op"tic\, a. [Gr. ? shadow + ? belonging to sight:
cf. F. scioptique. See {Optic}.] (Opt.)
Of or pertaining to an optical arrangement for forming images
in a darkened room, usually called scioptic ball.

{Scioptic ball} (Opt.), the lens of a camera obscura mounted
in a wooden ball which fits a socket in a window shutter
so as to be readily turned, like the eye, to different
parts of the landscape.