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RASA 8 Collimation help

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#1 hebar

hebar

    Lift Off

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  • Posts: 5
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Posted 15 January 2020 - 12:16 AM

Hello All!

My images showed tight stars in the center and elongated stars with different directions in the corners with two different cameras (asi1600 and asi183). I know for a fact the ASI1600 does not have tilt. Using ccdinspector it showed tilt so I believe it is out of collimation.

Using a defocused Star I attenpted to collimatate the scope. The inner most ring was slightly off-center favoring the left side so that confirmed it was slightly out of collimation. As I turned the push/pull adjustment screws by 1/2 to a full turn I barely saw the inner ring move. I kind of got lost with how much I turned each screw because i was not seeing much change.

For those that have attempted collimating their RASA. How sensitive was each adjustment? Did you have to loosen/tighten the screws a lot to see noticable change in collimation? Do you have a better strategy than what the manual says?

Clear skies! Thanks!

#2 bobzeq25

bobzeq25

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Posted 15 January 2020 - 01:30 AM

Hello All!

My images showed tight stars in the center and elongated stars with different directions in the corners with two different cameras (asi1600 and asi183). I know for a fact the ASI1600 does not have tilt. Using ccdinspector it showed tilt so I believe it is out of collimation.

Using a defocused Star I attenpted to collimatate the scope. The inner most ring was slightly off-center favoring the left side so that confirmed it was slightly out of collimation. As I turned the push/pull adjustment screws by 1/2 to a full turn I barely saw the inner ring move. I kind of got lost with how much I turned each screw because i was not seeing much change.

For those that have attempted collimating their RASA. How sensitive was each adjustment? Did you have to loosen/tighten the screws a lot to see noticable change in collimation? Do you have a better strategy than what the manual says?

Clear skies! Thanks!

I have a C8 RASA.  Haven't collimated it, sorry.  But this may help.

 

Started out with a similar problem with stars.  So bad they were donuts at the edge sometimes.  The tilt was not in collimation or the camera, it was in the Celestron adapter and/or my spacer.  Fixed it with a one piece PreciseParts adapter that replaced both.  Here's the result and more info.

 

https://www.cloudyni...sis-pp-adaptor/

 

You'd want this.

 

https://celestron-si...dapter_Rev1.pdf

 

Final image.  Click on it for acquisition details.

 

https://www.astrobin.../full/025umc/C/


Edited by bobzeq25, 15 January 2020 - 01:53 AM.



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