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Old 09-07-2014, 03:30 PM
SkyWatch (Dean)
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Join Date: Jan 2013
Location: Adelaide
Posts: 403
Quote:
Originally Posted by acarleton View Post
Hi Dean

1) i am not sure what you mean by a star test ... can you please explain
2) no i dont have a Bahtinov mask but i have been thinking about getting one. i dont think it is a focus issue because even when i change the focus slowly it never becomes clear.
3) Collimation is good, i use a laser collimator, i thought this was the issue so spent a long time on it.
Hi Aidan,

A star test is when you move a star in and out of focus and look at the image to see if there are any aberrations. Lots of material out there, but a good place to start for a basic explanation is: http://starizona.com/acb/basics/using_startesting.aspx
A Bahtinov mask isn't expensive, and you can even make your own (just google it to get templates etc): but it really helps when you are trying to get best focus.
I am always a bit wary of laser collimators as they can easily be off-collimation themselves in your focuser. Have you twisted it around in the focuser to make sure the laser doesn't move?

Good luck!

Dean
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