Assertion: telescope's design | /r/HasProperty | useful
Facets:
value: for astrophotography
type: PURPOSE
value: especially
type: DEGREE
Source sentences:
text: This design is especially useful for astrophotography, because it eliminates field rotation as it tracks the object through the night sky.
text: This section briefly discusses those catadioptric optical designs which are useful in professional applications, such as large observatories, satellite tracking facilities, military applications and industry.