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Dust on filter, should I be concerned?

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#1 Escape Pod

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Posted 24 October 2021 - 10:24 PM

I recently purchased a Lumicon 2” Oiii filter from CN classifieds for $155. They were listed as used in very good condition, and the seller did disclose that there were some dust particles. Upon receiving them, and being a bit of a perfectionist, I was a bit disappointed at how many dust particles there were. I of course attempted to remove them using my air blaster rocket  squeeze bulb, but to no avail.

 

Should I be worried about them impacting the view? The coatings themselves look flawless.  If so, is there a safe way to remove them? Or should I request a refund?


Edited by Escape Pod, 24 October 2021 - 10:25 PM.


#2 Cfreerksen

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Posted 24 October 2021 - 10:45 PM

I have yet to get a filter that didn't have a bit of something on it. Even brand new Chroma filters had some foreign debris.

 

A cup of distilled water with a drop of Dawn dish soap mixed in. Blow off the filter with a rocket air blaster and maybe a camel hair brush. Wash your hands thoroughly and take the filter, dunk in dish soap mixture. Use fingers very lightly to remove debris and any oils. Rinse with a clean squeeze bottle of distilled water. My Chroma filters were quite hydrophobic and the water ran off completely. No need for dabbing or blotting dry. Install them in the filter wheel and your good to go.

 

Chris


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#3 Escape Pod

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Posted 24 October 2021 - 10:53 PM

I have yet to get a filter that didn't have a bit of something on it. Even brand new Chroma filters had some foreign debris.

 

A cup of distilled water with a drop of Dawn dish soap mixed in. Blow off the filter with a rocket air blaster and maybe a camel hair brush. Wash your hands thoroughly and take the filter, dunk in dish soap mixture. Use fingers very lightly to remove debris and any oils. Rinse with a clean squeeze bottle of distilled water. My Chroma filters were quite hydrophobic and the water ran off completely. No need for dabbing or blotting dry. Install them in the filter wheel and your good to go.

 

Chris

Right on, Chris. I appreciate it!



#4 TOMDEY

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Posted 25 October 2021 - 01:43 AM

It should clean up OK... most likely. Just don't be too aggressive with trying to clean it. I've bought lots of used filters and about half were degraded and no good. Since then --- I always buy new.    Tom


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#5 Escape Pod

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Posted 25 October 2021 - 02:53 AM

It should clean up OK... most likely. Just don't be too aggressive with trying to clean it. I've bought lots of used filters and about half were degraded and no good. Since then --- I always buy new.    Tom

How visible / distracting would the dust be? Like specs on a diagonal or eyepiece, or more subtle?



#6 TOMDEY

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Posted 25 October 2021 - 04:08 AM

How visible / distracting would the dust be? Like specs on a diagonal or eyepiece, or more subtle?

Probably won't appear in the image at all. Our corneas generally suffer far more defects than our

telescope optics.    Tom


Edited by TOMDEY, 25 October 2021 - 04:08 AM.

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#7 DAG792

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Posted 25 October 2021 - 04:52 AM

If so, is there a safe way to remove them? Or should I request a refund?

Try a simple rinse with just distilled water. Refrain from touching the filter glass with anything. You are likely to cause more damage to the optical image that way. 

Regarding the dust and its impact on the telescopic image, you would be surprised at how dusty a telescope mirrors/lenses/filters can be and still deliver a flawless image. You probably wouldn't even notice it if you cleaned it. 


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#8 Escape Pod

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Posted 25 October 2021 - 07:18 AM

Thanks everyone! I’ve certainly heard the refrain about not being able to see dust or dew spots. I guess I worry more about filters because they’re much closer to the eyepiece. And I know when a spec of dust appears on a mirror or eyepiece it becomes visible.

Side question, is it considered poor form to store filters inside of a filter wheel? Assuming that caps are kept on the filter wheel at all times, are they considered as safe as the case the filter comes in?


Edited by Escape Pod, 25 October 2021 - 07:18 AM.


#9 LDW47

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Posted 25 October 2021 - 07:35 AM

I recently purchased a Lumicon 2” Oiii filter from CN classifieds for $155. They were listed as used in very good condition, and the seller did disclose that there were some dust particles. Upon receiving them, and being a bit of a perfectionist, I was a bit disappointed at how many dust particles there were. I of course attempted to remove them using my air blaster rocket  squeeze bulb, but to no avail.

 

Should I be worried about them impacting the view? The coatings themselves look flawless.  If so, is there a safe way to remove them? Or should I request a refund?

Just keep looking up, your worries are for naught  Wipe them off and in less than a minute there it is


Edited by LDW47, 25 October 2021 - 07:36 AM.



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