How to Collimate a Dobsonian with a laser collimator (basic steps)

[FrankRyanJr]

When I was starting out, I thought collimation was this really super-complex thing. Then when one of our astronomy club members showed me physically with their scope how to do it, I was surprised at just how simple it was! So I made a video as a basic guide for laser collimating a reflector,  in this case a 16'' GSO Dobsonian with a Kendrick laser collimator.

Obviously there's a lot involved in collimating and this video is not attempting to cover all those facets. It's intended as a quick explanation of the principle. I found that seeing the basics explained in simple terms without complication was key for me to then use that as a base to learn more. 

For beginners, there's a fine line between giving enough info to do the process correctly versus information overload. Once you get the basics down, it becomes clear over time the different areas that affect the outcome such as mirror springs, focuser slop, mirror quality, laser misalignment... the list goes on, they all certainly need to be understood but only by getting started and doing can you really learn. 
 

 

[Guest]

The key to collimating with a laser is to make sure that the laser is properly aligned first.  Once you get the laser sorted out and properly aligned then you can do the scope.   

[Clarkey]

13 hours ago, Mike Q said:

The key to collimating with a laser is to make sure that the laser is properly aligned first.

Agreed. A lot of the cheap collimators are out by quite a margin. However, most of them you can clean the 'gunk' out of the 3 collimating holes and get them accurately aligned. I made a jig out of lego to test mine against a wall 10m away.

[Guest]

10 hours ago, Clarkey said:

Agreed. A lot of the cheap collimators are out by quite a margin. However, most of them you can clean the 'gunk' out of the 3 collimating holes and get them accurately aligned. I made a jig out of lego to test mine against a wall 10m away.

I made a v block out of wood for mine.  Now the point just sits in the bullseye and spins, before it would move around the bullseye.  Took about 30 minutes to get it sorted out.