Assertion: eyepiece's length | /r/HasProperty | equal
Facets:
value: to 100mm
type: OTHER
value: to the height
type: OTHER
value: to extending this narrower light
type: PURPOSE
value: approximately
type: DEGREE
value: else
type: DEGREE
Source sentences:
text: Thus, the focal length of such a telescope would be equal to 100mm times 12, or 1200 mm.
text: However, since the radius of curvature is constant, and field sagitta (s) for the latter is given by s=h 2 /2R, where h is the field height, and R the radius of field curvature, i.e. it changes with the square of field height, it will require near constant accommodation, regardless of the (flat-field) eyepiece focal length (all else equal).
text: The objective effective focal length  is equivalent to extending this narrower light from the secondary focal point until it matches the diameter of the entrance pupil (diagram below, bottom).
text: The length is approximately equal to the height that you desire.