Splotchy Images

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atlguy
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Splotchy Images

Post by atlguy »

Hi,

I have a DayStar 60 mm Scout DS Solar Telescope that I used to get reasonable images from. Now these splotches appear. They are fixed in position and on every image. If I rotate the camera (ZWO 120 MC-S) they do not move. If I rotate the diagonal they do not move. I can't rotate the scope while it is mounted.

The splotches are just the most visible part the whole field seems "dirty".

So I assume this is the scope.

Any ideas what causes it?
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What I get now
What I get now
Capture_00001.png (636.11 KiB) Viewed 293 times

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Re: Splotchy Images

Post by Stardust5858 »

Definitely dust mots. Camera window or other elements in the light path need cleaning.


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Re: Splotchy Images

Post by atlguy »

Thanks I'll try cleaning the optics.


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Re: Splotchy Images

Post by Stardust5858 »

atlguy wrote: Sun May 16, 2021 9:29 pm Thanks I'll try cleaning the optics.
It's usually associated with a dirty camera lens, glass window on the chip rather than the telescope optics.


10ft x 6ft Solar RoR with Warm Room
Lunt 60mm Double Stack HA
80ed WL+ Lunt Hershal Wedge + Badder K-Line filter.
100mm AR + Lunt b1800 Ca-K module.
Neq6 Eq Mount.

2.7m Pulsar Dome.
11in Celestron SCT + White Light Filter.
70mm AR Stellavue.
12inch OO Newtonian.
Eq8 r Pro Mount.
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Re: Splotchy Images

Post by EGRAY_OBSERVATORY »

Exactly as Ella/Stardust5838 says, so if you rotate the camera and the Dust Bunnies - do not move, then the camera is the suspect.

A reminder then, that to always and immediately the open-end of the camera is as well as all optics - covered with the dust-caps as soon as they are opened to the elements, should deal with the problem in the first place...

Terry


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Re: Splotchy Images

Post by DeepSolar64 »

Yep. Dirt somewhere in the optical train.


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Re: Splotchy Images

Post by rsfoto »

If I rotate the camera (ZWO 120 MC-S) they do not move.
Hi,

This is the confirmation they are on the camera window. Also the size does confirm the distance from the window to the chip.

Dust on the front lens of the scope is not resolved. Dust in front of the Quark is also not resolved because they are far too away from the chip focus plane.


regards Rainer

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North 22° West 101°
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Re: Splotchy Images

Post by atlguy »

Thank-You all so much!

I had no idea about this dust mote issue. The camera cover looked ok until I took it out (which I only learned you could do after getting to page 47 of the manual). Both sides needed cleaning. Apparently in high humidity or dew point moisture can settle on both sides of the cover.

Here is a quick picture after cleaning.
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After Cleaning
After Cleaning
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Re: Splotchy Images

Post by EGRAY_OBSERVATORY »

The pic is not bad at all , in fact quite good atlguy.

Glad you found the "Dust Bunnies" and have moved them on.

"Both sides needed cleaning. Apparently in high humidity or dew point moisture can settle on both sides of the cover."
If kept covered or remaining in the EP holder/scope, cameras should normally be protected from humidity/dust, but obviously if the scope etc. is left outside (particularly in humidity above say 70%), then it should be - to bring it in-doors or at least somewhere under-cover where the humidity is much less than that.

For night-sky use particularly, when the scope etc., gets cold, then not to store it in a too-warm room at first, as condensation/damp won't do it any good...!!!

Humidity-meters are available - quite cheaply in one fashion or another, albeit not often accurate, so adjustable types are better, either electronic or mechanical.

Terry


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