Assertion: reflecting telescope's mirror | /r/HasProperty | convex secondary
Facets:
Source sentences:
text: There are many types of reflectors that solve the issue of where to focus the light in different ways such as Cassegrain reflectors which have a convex secondary mirror and a hole in the middle of the primary mirror.
text: Cassegrain reflectors have a convex secondary mirror and a hole in the middle of the primary mirror.
text: The concave tertiary mirror is positioned exactly twice as far to the side of the entering beam as was the convex secondary, and its own radius of curvature distant from the secondary.