Assertion: newtonian telescope's length | /r/HasProperty | eliminated
Facets:
value: from this expression
type: OTHER
Source sentences:
text: Coma will give an RMS aberration of 6.7m/f³, this leads to the tolerance d=0.034D where D is the mirror diameter, (rather surprisingly, the focal ratio and focal length are eliminated from this expression!) or about 1/30 of the mirror diameter.