a plane that is perpendicular to the axis of a lens, mirror, or other optical system and at which rays diverging from a focal point are deviated parallel to the axis or at which rays parallel to the axis are deviated to converge to a focal point.
CAN YOU ACE THIS QUIZ ABOUT “COMPLIMENT” VS. “COMPLEMENT”?
Take this quiz to see if you really know the difference between “compliment” and “complement"!
Question 1 of 11
“Compliment” and “complement” had a shared meaning a long time ago, but today they are no longer interchangeable.
Words nearby principal plane
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020