parallax

IPA: pˈɛrʌɫæks

An apparent shift in the position of two stationary objects relative to each other as viewed by an observer, due to a change in observer position.
(astronomy) The angle of seeing of the astronomical unit.

(transitive) To measure (a distance) based on parallax observations.
(animation) To produce an illusion of levels of distance by shifting layers at different rates.

Examples of "parallax" in Sentences

If they do, the parallax is not set for the range of the target you are using.
Not to mention that a fixed 10 power scope with no adjustable parallax is problematic at best, in an urban combat environment.
I get the impression the author in the last link should have actually read the Wikipedia article he linked to, because what he calls parallax it calls stereopsis.
They were as much puzzled about the meaning of the word parallax as I had been with regard to the word algebra, and only learnt what it meant when Brewster went to study for the kirk in Edinburgh.
The term parallax proving “caviare to the general,” they further explained that it meant the angle formed by the inclination of two straight lines drawn from either extremity of the earth’s radius to the moon.
To be able to do this, astronomers have developed what's known as parallax, which is then used to calibrate distance indicators for objects further away, which are then used to calibrate even further objects, etc ....
"Do not let us fear," wrote Lalande in his _Astronomie des Dames_, "do not let us fear to use the term parallax, despite its scientific aspect; it is convenient, and this term explains a very simple and very familiar effect."