I'm writing this article from Spain. I have not had time to do it while I was in Portland, as I had too many home-improvement projects going on and not time for observation either.
About a month ago, I got an invitation from Neil to collimate my Orion Mak 150 with his new artificial star. It is a work of art. :)
This article is about the process of Collimating my Orion Mak 150. It is a pretty tricky process and if Neil would have not been my side, I would not figured it out as the Orion documentation/pictures does not match the new collimation screw configuration on the back of my scope. Fortunately, I found some pictures on the net, that matches my scope for illustrating the below process. Again, Neil saved my day when it came to patience and technical knowledge figuring out how the whole thing works. I'm merely documenting the process that he discovered. :)
In order to collimate the scope, you have to point it to the artifitial star and take it a bit out of focus to see how the rings are compressed. The goal of the collimation process is to have equal/even rings around the rings. I learned that I can't collimate on the edge of the lens, as the lens/mirror has a curve and if you collimate it perfectly on the edge, it won't look OK in the center. So, we collimated in the center of the lens.
How do you find the center of the lens? Another nifty tool/trick from Neil is to use an illuminated eye-piece with a cross-hair to find the center.
The whole collimation process is about tweacking the collimation screws, but the trick is to find out which screw does what, and in which direction they turn.
Also, it is important to note that every time you tweack a screw, you have to wait a few seconds to see the effect of the correction.
Overall, it was a complicated process, but Neil figured it out!!! :) ...and I learned a tone during the process. Thanks Neil!!!
I added a couple of pictures where you can see compressed rings at the bottom, and what you want to do is to push the up so they are all even around the circle. The other picture shows you the screw configuration, where there is a big screw and a small screw side by side. There are in total 3 pairs of screws (1 big and 1 small).
OK, so how do you pull the center of the rings up to create even-rounded rings?
If the white rings are compressed at the bottom, you lose (counter clock-wise) the big screw at the top (1/4 of a turn) each time, to move the center doughnut up towards the top (or in the direction of the bigger screw that you are losening up), at the same time you will use the small screws to tighten (clock wise) and keep the mirror tight. That is why it is important to lose 1/4 of a turn with the big screw and tighten 1/4 of turn with the small screw, wait a few seconds and see what the effect is before you get too excited and overdo it like I would. :)
I hope it helps!