Assertion: newtonian telescope's mirror | /r/CapableOf | edge sharp
Facets:
value: perfectly
type: DEGREE
value: at the same time
type: TEMPORAL
Source sentences:
text: You cannot, of course, see the inner opening and the mirror edges perfectly sharp at the same time, but the small peephole will improve your "depth of focus" and keep the unsharpness tolerably low.