About Maximapedia


APERTURE (from Lat. aperire, to open), an opening. In optics, it is that portion of the diameter of an object-glass or mirror through which light can pass free from obstruction. It is equal to the actual diameter of the cylinder of rays admitted by a telescope.

Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)

Privacy Policy | Cookie Policy | GDPR