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Old 13-11-2010, 12:22 PM
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pmrid (Peter)
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Collimating a HyperStar

I would be interested to hear the preferred methods of others for collimating a HyperStar. I flirted with one briefly with my old C14 but never really cracked the collimation. Not to be deterred, I am now fitting it (with a suitable modifications) to my new EdgeHD 1400 and this time am determined to persevere.
I gather that the out-of-focus star technique is not very useful and that the best way is with an in-focus star. Any variations on either theme? And other ideas or suggestions?

peter
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Old 15-11-2010, 01:45 PM
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blink138 (Pat)
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Hyperstar

the only other member i know of that does hyperstar ccd is mark (multiweb)
give him a bell
pat
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Old 15-11-2010, 02:01 PM
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mch62 (Mark)
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Peter I have an Edge 8 with Hyperstar and from the distructions that came with the Hyperstar3 unit it comes down to trial and error basically . When I got mine all the screws were loose but fortunatly when I started from scratch with the lens bottomed out and all adjusting screws not touching it did not need collimation. Stars are pin points from edge to egde on my QHY10 at least. I did try (to see the results) adjusting the screws to see what difference it made and found it did not require much to see the stars change shape in the corners .
Peter have you got the 14"yet ? I found even at f10 with the QHY10 edge performance is supperb with stars pin points in the corners of the field. I was shooting at F10 untill my hyperstar turned up and am interested to see when the focal reducer from celestron turns up what the performance will be with it.
One thing to be aware of with the Edge system is the rear distance when using eyepieces and cameras at F10 , as it is fairly critical. I was initialy stumped when viewing with 2 "eyepieces the stars were out of focus between the edge to the center and found that because I was using a 2"diagonal I had the distance to short. Once i got this sorted with a spacer all is fine now.

Mark

Last edited by mch62; 15-11-2010 at 02:14 PM.
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Old 16-11-2010, 06:03 AM
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Quote:
Originally Posted by mch62 View Post
. I was shooting at F10 untill my hyperstar turned up and am interested to see when the focal reducer from celestron turns up what the performance will be with it.
Hi Mark and thanks. Yes. The HD14 is up on it's Titan and ready to go - I already had a HyperStar but of course hadn't appreciated that the EdgeHD requires a modified HyperStar - so now I'm waiting again while an adapter ring staggers across the Pacific from Starizona.
Because I will have to partially disassemble the HyperStar in order to fit the adapter, I have decided to reassemble it with a 30 thou gap (using feeler gauges) in the hope that this should place it close enough to collimation.

Also, and rather than wait for Celestron to get their reducer act together, I decided to have a crack at the Optec Lepus reducer (.62) that OPT claim is designed for use with the HD optics. It too is 'coming'. If the clouds ever part, I'll let you know how it performs.
Peter
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Old 16-11-2010, 07:09 AM
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Peter,

You might some info on Hyperstar collimation here: http://tech.groups.yahoo.com/group/fastar

Cheers,
Rick.
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Old 16-11-2010, 04:38 PM
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pmrid (Peter)
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Quote:
Originally Posted by mch62 View Post
One thing to be aware of with the Edge system is the rear distance when using eyepieces and cameras at F10 , as it is fairly critical. I was initialy stumped when viewing with 2 "eyepieces the stars were out of focus between the edge to the center and found that because I was using a 2"diagonal I had the distance to short. Once i got this sorted with a spacer all is fine now.
Mark, can you give me some idea of what the optimal distance is. I can't find any mention of this in the literature.
Peter
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Old 16-11-2010, 04:38 PM
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pmrid (Peter)
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Peter,

You might some info on Hyperstar collimation here: http://tech.groups.yahoo.com/group/fastar

Cheers,
Rick.
Thanks Rick.
Peter
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Old 20-11-2010, 10:42 AM
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Trial and error basically. The good thing is once its done it seems to hold quite well.

To make it easy I defocus so the stars are like small donuts and use my CCD in "live-mode" making adjustments. The goal is to get a concentic out of focus star at the centre of the field. Once this is done you can refocus so that stars are almost at focus and refine the collimation. Finally, I'll check in focus the centre and 2 opposite corners of the image for the shape of star images. I'm yet to get the collimation spot on - I suspect the CCD is very slightly out of square - but I'm pretty happy with edge to edge sharpness none-the-less.

Terry
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Old 20-11-2010, 11:58 AM
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pmrid (Peter)
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Trial and error basically. The good thing is once its done it seems to hold quite well.
....

Terry
Thanks terry. That seems to be the sensible way to go.
If I ever see some sky...
Peter
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