Darrell Hensley said:
Hi Gene,
Here's an instructional video on collimating a SCT. It is the first part of I think 3.
http://www.youtube.com/watch?v=kJdo8RwDwi4 Althogh this isn't an antare's laser collimator, it should be of some help.
Good Luck,
Darrell
Darrrell:
Actually that was part 3.
It is worth noting that this technique requires that the telescope first be collimated by a star test. The concept here is that you collimate the scope using the star test. Then you insert the laser, mark it's orientation and see where the reflected beam lands on the laser and then mark that position. This is a preparation step.
Then the next time you want to collimate your scope, you insert the laser being careful to align the orientation marks, and then adjust the secondary to duplicate the original marking of reflected beam. And then the final step it star collimation...
Essentially you are just using the laser to try to repeat a previous star test. I don't know of anyone who actually recommends or uses this technique, maybe Uncle Rod Mollise can comment but I think one is better off just starting out with the star collimation and skipping the laser.
Lasers are a valuable tool in collimating Newtonians because the beam reflects off both the primary and the secondary mirrors in its travels and because Newtonians are typically fully adjustable for collimation. In an SCT, the light only reflects off the secondary mirror and in any event the primary is not adjustable. So collimation is a compromise and the best technique is to simply collimate the scope using a star. That way the light reflects off both the primary and the secondary and a best fit is possible.
Jon
