Help with Egg shaped stars

Discussion of using SharpCap for Deep Sky Imaging
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Eggeffect
Posts: 2
Joined: Wed Sep 02, 2020 8:55 am

Help with Egg shaped stars

Post by Eggeffect »

I took theses images about two months apart M15 and Orion Nebula,they are live stacked then saved as seen in sharp caps, as you can see both show egg shaped stars, Could this be a collimating or tracking issue
My scope is a skywatcher mak newt 190
Camera Altair 294c pro tech
Guided 290 go pro
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admin
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Re: Help with Egg shaped stars

Post by admin »

Hi,

it's kind of hard to tell based on the images because of the low resolution – perhaps you could share links to higher resolution versions stored on some other image sharing site like Flickr.

As a general guideline, if the star shape is consistent all across the image then it's quite possibly a guiding problem. If it varies in different areas of the image then it's more likely to be an optical aberration (collimation problems, coma, flattener separation distance, etc).

cheers,

Robin
Eggeffect
Posts: 2
Joined: Wed Sep 02, 2020 8:55 am

Re: Help with Egg shaped stars

Post by Eggeffect »

I've opened a flicker account and posted there
https://www.flickr.com/photos/191795874 ... ed-public/
https://www.flickr.com/photos/191795874 ... ed-public/

hopefully it will work
Any hints and tips also on general image quality greatly apricated also. :)
Thanks
chongo228
Posts: 174
Joined: Fri Nov 24, 2017 3:34 am

Re: Help with Egg shaped stars

Post by chongo228 »

It looks like all the stars are oblong from the bottom left to upper right side. Perhaps a tracking error or cord snagging?

It doesn't appear to be radiating from the center which would indicate back spacing issues.
BlackWikkett
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Re: Help with Egg shaped stars

Post by BlackWikkett »

Hi,
This looks like mount / tracking problem as the oblong is in the same direction all over the frame. If this was an optical issue the oblong stars usually tend to be at the edges of the frame and point towards the center. Are you using guiding?

-Chris
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