Collimation Help Celestron C6 SCT

1 reply104 views
A. Wegdan avatar
I'm having an issue with collimating my scope and for the life of me I cant seem to figure it out.

Now I know the collimation basics, and procedures.  The issue im facing is this, yesterday I had slight mis-collimation so i proceeded with doing a visually aided collimation on Capella.

After I was satisfied I slewed over to my target "The bubble nebula NGC 7635". My plate solving didn't work, when i looked at the screen the stars were all streaks. Now you might say its polar alignment or some other sort of error but my live screen is going at 300ms and high gain and the stars were actually small streaks. 

I proceeded to do another collimation and it went all good until i went out of focus to the other side, I usually collimate by taking the star out of focus in one direction then confirming by taking it out of focus the other direction. What I'm consistently seeing is that one direction of focus is collimated the other is not. When i collimate on that direction the other goes out of collimation. 

What am i missing here? Also seems like after the collimation the direction I'm pointed at is fine, but when i move to target the stars are streaks …. I was scratching my head all night and got so frustrated and went to sleep.

Below is an illustration of what I descried above (excuse my terrible art) , and a picture of Vega I took along time ago with another symptom ( though at that point I had no streaks issue) 

Any insights on what the issue could be would be greatly appreciated.

 Clear Skies 
 
Helpful Engaging
churmey avatar
Ahmed,

I'm sorry your having issues. I'm not sure what is going on here and don't have much advice too offer.  I would however suggest that you ensure that all your corrector plate screws are tight (these can loosen over time). Then I would ensure that your secondary collimation screws are tightened evenly amongst the three. Not over-tightened but that they are firm. From this position, I would begin my collimation process and only backing off the collimation screws in very small turns until you meet collimation. Once complete, see if you have the same issues or if this has corrected it.
Helpful Respectful
Related discussions
Help with identifying optical aberration of my system
Hi All, I bought a used quadruplet from Teleskop Services last July (with a discount of course) and the stars have never been sharp pinpoints, but I feel like the problem is increasing more and more. It was my first refractor and my starts in the ast...
Collimation basics and procedures directly address author's suspected collimation issue.
Mar 7, 2021
Focus issue or collimation issue?
I am setting up an AG Optical 12.5" iHW (f/3.9 Harmer Wynne design at roughly 1250mm focal length) and I am shooting with a QHY600 along with Chroma filters. I noticed that some nights I get these nice rings around stars on the RGB filters. Some...
Discusses distinguishing between focus and collimation issues affecting star quality.
Aug 26, 2024
Why are my stars shaped like flat discs???
If I hadn’t seen it, I wouldn’t believe it was possible. A little backstory: For various reasons, I’ve struggled with collimation on my Meade SN8. Finally feeling I got it down, I went out 3 nights ago and got the best collimation I’ve ever had. This...
Addresses collimation struggles causing poor star appearance and quality.
Jul 27, 2024
I Haven't Yet Mastered Collimation with the Edge HD 8
Using the OCAL 3.0 Collimator is proving to be more difficult than I thought. I have tried collimating with and without reducer, with and without OAG and with and without the 21mm filter holder. I cannot seem to get the red circle to line up with the...
Covers collimation challenges and techniques for telescope optimization.
Jun 1, 2024
Refractor collimation question
When i defocus, the center of the defocused stars are all shifted in the same direction across the field. If the primary cell was out of collimation, would the center of defocused stars be radially off center around the field? Or is this tilt? The pr...
Explains collimation diagnosis through defocused star behavior analysis.
Sep 11, 2024