Need help troubleshooting star shape

Equipment Troubleshooting Artifacts
5 replies•199 views
daflye avatar
daflye avatar
Hello,

Does anyone know why my stars look like this? Didn't have this problem before. Recent change is a new ASI2600MC camera and I cleaned my telescope (Explore Scientific FCD100 Triplet Refractor). I think I might have messed up the location of the front glass.

Rest of image looks fine. Just the stars look weird.

Any help would be greatly appreciated.

Thanks!

SemiPro avatar
SemiPro avatar
If you live in a cold location, it could be pinched optics.
Dan Brown avatar
Dan Brown avatar
That's an odd pattern. Did you remove the new camera and look for debris/objects in the light path? Do you have the ability to attach an eyepiece?
Dan
Bob Lockwood avatar
Bob Lockwood avatar
Dan Brown:
I think I might have messed up the location of the front glass.


What do you mean by this? Did you remove it?
Tony Gondola avatar
Tony Gondola avatar
The symmetrical shape of the diffraction suggests pinched optics to me. That could have been caused by over-tightening something when you put the objective back together. Also, I hope you indexed the rotational relationship between the elements. These elements have residual wedge (differing edge thicknesses) that is averaged out during assembly. It's extremely important that you maintain this positioning.
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daflye avatar
daflye avatar
Thanks, everyone.

The outside temperature last night was in the teens. So hopefully that was the reason.

If that is not it, I'm pretty sure I messed up the front glass. There was something on the glass on the inside of the scope, so I took out the front glass to clean it. But I didn't know what I was doing and moved alignment set screws while doing it. There are some in the back and some in the front of the glass to change the angle of it. So there's a possibility that the glass is no longer in perfect alignment... or maybe too tight. I'll have to research on how to get this fixed.

But besides the stars, the image looks great.

Thanks for chiming in.

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