Assertion: reflecting telescope's mirror | /r/HasProperty | aligned
Facets:
value: very precisely
type: DEGREE
value: during manufacturing process
type: TEMPORAL
value: perfectly
type: DEGREE
Source sentences:
text: The eyepiece can also be behind the parabolic mirror, in which case the secondary mirror is aligned so that the light passes through a small hole in the objective lens to meet the eye of the viewer.
text: The mirror may also need to be aligned or “collimated” sometimes.
text: Five seconds are allowed between exposures, but one second is reserved for the mirrors and instrument to be aligned, leaving four seconds for the structure.
text: To eliminate the problem of image shifting during focusing and also to eliminate optical alignment tasks (often called collimation) for the user, the primary mirror can be perfectly aligned during manufacturing process and then fixed securely within its cell.
text: A reflecting telescope is also harder to maintain: The mirrors need to be very precisely aligned (this is called collimation), and this can be a laborious process.