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CCDInspector One-Star Collimation & Polaris

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#1 Salacious B Crumb

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Posted 15 March 2019 - 08:20 AM

Trying to kill some time here while waiting for the CP4 to come back.

 

I bought the CCDInspector and I’m planning to use it to collimate my RC8. Has anyone done this by using the Polaris, meaning is it bright enough for one-star collimation and I could do this now without slewing or tracking? Has anyone done this and any thoughts if the QSI or the Lodestar would be better suited for this purpose? I briefly tried the multi-star collimation option the other night and the program kept telling me that my FOV is not large enough (or something similar). Further, any other tips before I start to rotate those pesky screws of the secondary mirror (my plan is not to touch the primary mirror unless absolutely necessary).

 

 

Thanks,

 

Mikko



#2 drmikevt

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Posted 15 March 2019 - 08:53 AM

Your  RC8  plus QSI has a plenty large enough FOV.  The problem, most likely, was there there were not enough stars in your FOV.  The program likes a very full star field for collimation.  It will definitely be better for you to first polar align your mount and start tracking.  I normally take 30sec images through an L filter to feed into the program for collimation.  Tends to work well.  

 

Collimating your RC should be 3 distinct steps (in my opinion - others have other opinions)

 - First, use a laser to make sure your camera is properly aligned with the central spot on the secondary

 - Next, use a perfectly centered out of focus star to collimate the primary to the camera (described here: http://www.deepskyin...re_Ver_1.0.pdf)

 - Finally, use CCDI to collimate the secondary.  There are other ways to collimate the secondary and some people don't fully trust CCDI, but it seems to give me good results.  I think that using a full star field will give better results than a single star. 



#3 Salacious B Crumb

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Posted 15 March 2019 - 09:17 AM

Thanks Mike. I did already the laser alignment and I think it's OK. I say this as I find it difficult to see exactly where the laser is pointing behind the secondary or where it hits back to end of the tube. I guess using a single star collimation AND tracking would be difficult when I have to defocus the star so much. This of course unless I refocus the Guide Camera after doing this. Not sure if one method is better than another (single versus many stars).

 

 

- Mikko




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