Telescopes: How important is buying a Collimator?

Answer 1

Do you mean a laser collimator? I have never had one, and I have had no problems collimating my 8" and 6" reflector 'scopes by "hand". Once you learn how to do it and do it a couple of times, you'll think it is easy, and you will realize you don't need a special device to do collimations.

I did get a pin-hole eyepiece, though (eyepiece tube with a foil end and a small hole exactly in the center of the foil, with no lens) -- that makes collimations easier.

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Answer 2

If the focal ratio of your Newtonian is f/6 or greater, you probably don't need anything more than a simple sight tube. Orion supplies a nice little one free with every Newtonian they sell. Alternatively, you can make one yourself from an old 35mm film cannister by cutting off the bottom and punching a hole in the top.

For shorter focal ratio Newtonians, you need a Cheshire eyepiece. The one Orion sells works just fine:
http://www.telescope.com/control/product/~category_id=scope_tune-up/~pcategory=accessories/~product_id=03640

Laser collimators are useful only for double checking the collimation of scopes already collimated with a sight tube or Cheshire. Used by themselves, they can easily mislead you.

Collimating a Schmidt-Cassegrain is a totally different process, and is done with a star, and needs no special equipment, though replacing the collimation screws on the secondary with Bob's Knobs makes the process much easier:
http://www.bobsknobs.com/

Answer 3

It makes the job of collimating a reflecting telescope easier but it is quite easy enough to do without it (depending on the size of the telescope). Large telescopes really need 2 people to collimate them anyway...

Answer 4

That can be a very expensive piece of equipment and you should not need one.