What is "scioptic ball"

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.

The scioptic ball is a universal joint allowing an optical instrument mounted on a ball to be swiveled to point anywhere in a wide arc. It was inspired by studies of the human eye. It has a number of applications. The scioptic ball may provide a firm anchor for a microscope, camera or telescope allowing it to be swiveled in all directions, for example to follow the course of an eclipse or for drawing panoramic views. Scioptic balls have been used as camera obscuras, projecting images from the outside on walls in darkened rooms. Scioptic balls have been used simply as light sources. It was an early example of a type of wide-angle lens.