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Collimation help
Hi guys,
Been trying to get my head around collimation these last few days its kind of doing my head in. I did a star test last night and noticed that when it is out of focus I dont get a complete circle, one of the edges has been cut. When I use my laser collimator the red dot shines into the middle of the circle on the primary. However when i move the telescope up or down the dot the comes back up to the target moves a bit. It might be lined up perfectly when I have the dob at say 45 degrees but if i move it up or down from there the laser dot will move slightly out of the centre. (I mean centre of the target, the dot stays in the centre of the primarys circle the whole time)
After getting everything lined up i have taken a look into the focuser and notice that the primary mirror isnt completely showing - kinda like my star example. I have attached a picture but its real dark, hopefully you can see what I mean. When I look down it the circle from the primary lines up with the middle of the secondary but all of the primary mirror is not in view. Hopefully I have explained myself well enough so that someone here can point me in the direction of how to fix this.
I never even noticed until last night and for the most part I can get everything into focus quite well. But I have no reference to go by as to whether what i am seeing is as good as it could be as have never looked through another telecope before. And to be honest would never have known if i didnt see an article about collimating with a star.
Cheers in advance,
Pat
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