collimate

The unit utilizes new patent-pending Collitron eyepiece holders that allow the user to precisely collimate the unit without tools, and both sides focus with non-rotating helical motion.

So what are we trying to do when we collimate a Newtonian?

This is why you should collimate your scope--you want to ensure you're viewing the very best part of the primary's focal plane.

All reflector owners should know how to collimate their telescopes.

That's why when I collimate my scopes, I finish by tweaking the secondary to get the alignment exactly right--I trade an imperceptible shift in the illumination pattern for precise collimation.