After being reflected by a mirror or other high-quality reflective surface, light re-enters the autocollimator and is focused by the objective lens.
(light; re-enters; the autocollimator; T:After being reflected by a mirror or other high-quality reflective surface) (light; is focused; by the objective lens; T:After being reflected by a mirror or other high-quality reflective surface)
light light
re-enters is focused
the autocollimator T:After being reflected by a mirror or other high-quality reflective surface
by the objective lens T:After being reflected by a mirror or other high-quality reflective surface