Collimating Orion Skyview Deluxe 8" Newtonian

Hi - I am new to this forums and need some assistance.
I just had my scope (Orion 8" Newtonian) collimated by a "professional". When I brought it home, I sky tested it on a normal dry evening. The results were good using a 20mm eyepiece, but not good when using a 12.5mm eyepiece. I wrote back to the professional and the response was that the result of using a 20mm meant that the scope was collimated, but the night was not a good night for viewing with the 12.5mm.

I leave in the NY Long Island area.

The scope now does not work well with the 20mm on one of the best nights of viewing.
Here are my questions.
1. How can I collimate this scope so I do not have to bring it a professional?
2. If the primary mirror does not have a center spot or line, is there a way to collimate?
3. I purchased a Orion LaserMate Collimator, but I am not really sure how to use it. Can any one assist?

Thanks in advance.

I'm surprised no one has responded to you yet. The first step is to go to the Search Forums on the right hand side of the web page. Go back 4 to 5 years and you'll find a wealth of threads on this topic. Also do a Google search as there are a number of sites that address collimating a newtonian. (Or do what I did - buy a refractor!)

For hands on assistance, find a local astronomy club; when people get together to share a common interest they tend to be cordial and helpful.

Theodore Goodman said:

Hi - I am new to this forums and need some assistance.
I just had my scope (Orion 8" Newtonian) collimated by a "professional". When I brought it home, I sky tested it on a normal dry evening. The results were good using a 20mm eyepiece, but not good when using a 12.5mm eyepiece. I wrote back to the professional and the response was that the result of using a 20mm meant that the scope was collimated, but the night was not a good night for viewing with the 12.5mm.

I leave in the NY Long Island area.

The scope now does not work well with the 20mm on one of the best nights of viewing.
Here are my questions.
1. How can I collimate this scope so I do not have to bring it a professional?
2. If the primary mirror does not have a center spot or line, is there a way to collimate?
3. I purchased a Orion LaserMate Collimator, but I am not really sure how to use it. Can any one assist?

Thanks in advance.

A word to the wise:
Google: "collimation" plus "forum," and "Pensack" or "Menard" or "Carlson."
Then ask your question.

Bill Meyers

Thanks all, your information was very helpful.

Here is a nice link:

http://www.oarval.org/collimatE.htm

A good tip: don't worry about offset yet (mechanical collimation)

here's the site for seeing forcasts:

http://www.cleardarksky.com