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Eggy stars - my sensor too close?


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Your 3 minute sub has little or no tilt, but does show guiding errors, all the stars are elongated at 45 degrees to the horizontal.

You need a short exposure, stretched if necessary, to show star shapes without guide errors.

Michael

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2 hours ago, michael8554 said:

Your 3 minute sub has little or no tilt, but does show guiding errors, all the stars are elongated at 45 degrees to the horizontal.

You need a short exposure, stretched if necessary, to show star shapes without guide errors.

Michael

Thank you. I was getting the same issue with a 30 second sub too. I haven't got the inage on me as yet, it's on my laptop. But will post it soon and really hoping to get out and test the 5mm spacer. 

 

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Update number 1054. I managed to get out with my scope last night and try out testing the additional 5mm of extra spacing in my imaging train. It appears to be so much better, there's just and issue of tilt in the bottom left corner now. This is a 30 second single sub on Regulus my test and focus star. So my back spacing is now 60mm. This consists of long tube version of sw 72ed, sw rotator, ovl FF, 60mm of spacing including zwo tilt adjuster and zwo 294mc pro. Just got to figure out which grub screw to alter on my tilt adjuster to sort eggyness in bottom left. I'm much happier than I was Tuesday night when it was all pants before the 5mm spacing was added for Friday night test. I'll add that guiding was good when it was first clear but then the transparency deteriorated a lot. 

Regulus-Flo-30s.jpg

Edited by AstroNebulee
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  • 2 weeks later...
Posted (edited)

Hopefully the final update of my eggy star issue.  I've added a 1mm T2 spacer to my imaging train and another slight adjust to the tilt adjuster and on this 3 min crudely stretched M51 the stars are much rounder now and I'm happy this has been mechanically sorted (it may need another thin spacer to be added in the future) Then whilst searching through my star tools software there's a heal function with warp or redistribute algorithm to help with any oval eggyness in images as long as it's not to bad, so tried this and wow. (I know it's cheating in the processing but mechanically it looks OK too) I'm so so happy now, after 2. 5 months of adjusting, purchasing parts, waiting for clear skies, stress, more adjustments and ballache I think I'm finally hopefully there. 

First image is the crudely stretched 3 min sub without the Startools heal function 

And the second is using the Startools repair module then redistribute algorithm. 

 

This thread is entwined with this thread about scope or sensor tilt 

Cheers 

Lee 

M51-Flo-test 8-3-22.jpg

Redistribute-stars-star-tools.jpg

Edited by AstroNebulee
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