Some finderscopes have crosshairs to mark exactly where the main telescope is looking.

The Koribu's main telescope was swinging around to point at the first dragon.

The third mirror of the main telescope which sends the light down into the observing room can be moved above three different positions.

Its main telescope, smaller than those used by some amateurs, is 40 years old and liable to break down on cold winter nights.

Students could frequently be found using both the main telescope and any number of smaller instruments.

The main telescope could be bypassed to a smaller wide angle optic, but using the same tube.

The new main telescope mounted in the observatory is a Celestron C-14.

When we watch the whole system through our main telescope, it's a pretty sight.

The rotation axis of the main telescope needed to be exactly horizontal.

Message Bearer's main telescope was the equal of any astronomical installation on the world they had left behind.