"Aperture - "an opening, hole, orifice," from Latin apertura "an opening," from apertus, past participle of aperire "to open, uncover," from PIE compound ap-wer-yo- from ap- "off, away" (see apo-) + root *wer- "to cover." In optics, "the diameter of the exposed part of a telescope, microscope, etc.," from 1660s."
For a term established that early, why use an analogy?
introduce lay people to hard concepts
Aperture (or exposure for that matter) isn't one of those.
Short-legged analogies are among the first reasons why misconceptions flourish. IMO if an analogy can be avoided it better be.