TheSkySearchers

Posted: **Mon Apr 18, 2022 10:20 am**

Hi gang,

So I took the opportunity last night with semi clear skie for some lunar observations. I actually used my 6mm BCO for the first time in a while and noticed a number of spots, which severely affected my views.

I thought it was a matter of cleaning the lens, but later at home I couldn't clean the eyepiece and it has these spots. I use Baader wonder fluid and cloth. I think i got a few of the spots cleaned but I most remains there.

Can anyone provide any info is this beyond repair?

The images here were taken at home against a light. I hope someone can recognise what its's about.

Posted: **Mon Apr 18, 2022 4:44 pm**

Well that is amazing! I cannot say I have ever seen that in a eyepiece before.
You have cleaned both the eye lens and field lens of the eyepiece?

Posted: **Mon Apr 18, 2022 4:48 pm**

If it's not cleanable, I've (rarely, thankfully) seen a case or two when coatings went defective at localized points.

Posted: **Mon Apr 18, 2022 4:49 pm**

I assume you see the spots when you hold the BCO against the light. When you observe the Moon or terrestrial targets during the day with telescope do you see the sharp spots in the field of view?

Posted: **Mon Apr 18, 2022 4:58 pm**

notFritzArgelander wrote: ↑Mon Apr 18, 2022 4:48 pm If it's not cleanable, I've (rarely, thankfully) seen a case or two when coatings went defective at localized points.

That was my first though as well, but seemed a bit excessive for that in a new eyepiece.
Hopefully it is not.

Posted: **Mon Apr 18, 2022 5:23 pm**

Lady Fraktor wrote: ↑Mon Apr 18, 2022 4:58 pm
notFritzArgelander wrote: ↑Mon Apr 18, 2022 4:48 pm If it's not cleanable, I've (rarely, thankfully) seen a case or two when coatings went defective at localized points.
That was my first though as well, but seemed a bit excessive for that in a new eyepiece.
Hopefully it is not.

Something got by the quality check? If not in focus it might not matter. In this case it does.

Posted: **Mon Apr 18, 2022 5:45 pm**

PS If cleaning eye and field lenses without taking the EP apart doesn't fix, I'd return for a replacement.

Posted: **Tue Apr 19, 2022 10:01 am**

Thank you all for the replies.

So a bit of clarification, I have received the set (q turret with 4 eps) as a gift some 5 years ago. I have seldom used the 6mm, mainly due to eye relief and me chasing for DSOs.

I have to be honest, at the beginning I haven't really taken good care of the eyepieces (and cleaning wasn't really done the way it should have been). Interestingly enough, the most used EPs are in good condition and the views are really good.

I have noticed these spots when viewing the moon last night and it's kind of painful since the barlowed view with my frac was really sharp and awesome (if the spots werent there).

I tried cleaning and really was careful not to apply too much pressure, so just curious how much pressure can the coatings take. Any other advice on what I can do will be appreciated.

I am inclined to re-purchase the 6mm ep (as the BCOs are really good, especially compared to BST 5mm and the wide field 24mm, which is good but not as sharp) if I can't get it cleaned properly. I guess it's the tax on learning

Posted: **Tue Apr 19, 2022 10:31 am**

Thanks for sharing your story in more detail. The coatings can definitely be damaged by cleaning. I almost never clean mine because I want the coatings to last as long as possible. Learning tax is a good way to think of it. It’s a good ep and I hope the replacement serves you well.

Posted: **Tue Apr 19, 2022 12:44 pm**

Hi. First can you make a positive determination that the spots are on the external surface of the eye lens or the field lens? I would want to do this first, using a strong magnifier, before cleaning as want to clean where the dirt is. If the spots are easily seen as distinct dark shapes when lunar viewing then more likely they are on the field lens since that is closer to the field stop. If they are more nebulous when observing and cause the view to blur then the eye lens might be the better culprit.

In any event, before doing any "aggressive" cleaning, very important to ensure all other dirt and dust is off the lens as you do not want those particles scratching the coatings with an aggressive clean. I presume you are using a Q-Tip to clean the surface, which is fine. When a spot is stubborn to get off using a cleaning fluid or alcohol, it might mean that the spot is biological (airborne tree sap, pollen, etc.) and needs enzymes instead to loosen or dissolve it. So you can try using some of your own saliva for that. Just wet the Q-Tip, then place it on the lens holding it in place for 15 seconds or so. Reason for that is to let the enzymes do their work first. Actually, this is a good practice for stubborn spots when using a solvent also like alcohol. So after some set time then swipe it to see if the spot was removed. If not, just repeat a second time. When you let the solvent or enzymes sit on the lens surface for a bit of time, they will generally loosen the or dissolve the spot so no aggressive pressure is needed. If you do want to try some aggressive pressure, just do it with a single swipe. Multiple swipes may cause the removed spot to then be moved across the lens and whatever hard material that spot/dust is made of could scratch the optic. That is why it is recommended to only do one swipe then get a fresh Q-Tip or cloth.

If that works and you used saliva, then follow up the cleaning with alcohol or distilled water to get any remaining compounds from the saliva off.

Good luck!

Posted: **Tue Apr 19, 2022 1:10 pm**

WilliamPaolini wrote: ↑Tue Apr 19, 2022 12:44 pm Hi. First can you make a positive determination that the spots are on the external surface of the eye lens or the field lens? I would want to do this first, using a strong magnifier, before cleaning as want to clean where the dirt is. If the spots are easily seen as distinct dark shapes when lunar viewing then more likely they are on the field lens since that is closer to the field stop. If they are more nebulous when observing and cause the view to blur then the eye lens might be the better culprit.

In any event, before doing any "aggressive" cleaning, very important to ensure all other dirt and dust is off the lens as you do not want those particles scratching the coatings with an aggressive clean. I presume you are using a Q-Tip to clean the surface, which is fine. When a spot is stubborn to get off using a cleaning fluid or alcohol, it might mean that the spot is biological (airborne tree sap, pollen, etc.) and needs enzymes instead to loosen or dissolve it. So you can try using some of your own saliva for that. Just wet the Q-Tip, then place it on the lens holding it in place for 15 seconds or so. Reason for that is to let the enzymes do their work first. Actually, this is a good practice for stubborn spots when using a solvent also like alcohol. So after some set time then swipe it to see if the spot was removed. If not, just repeat a second time. When you let the solvent or enzymes sit on the lens surface for a bit of time, they will generally loosen the or dissolve the spot so no aggressive pressure is needed. If you do want to try some aggressive pressure, just do it with a single swipe. Multiple swipes may cause the removed spot to then be moved across the lens and whatever hard material that spot/dust is made of could scratch the optic. That is why it is recommended to only do one swipe then get a fresh Q-Tip or cloth.

If that works and you used saliva, then follow up the cleaning with alcohol or distilled water to get any remaining compounds from the saliva off.

Good luck!

Excellent methods.

Posted: **Fri Apr 29, 2022 2:31 pm**

WilliamPaolini wrote: ↑Tue Apr 19, 2022 12:44 pm Hi. First can you make a positive determination that the spots are on the external surface of the eye lens or the field lens? I would want to do this first, using a strong magnifier, before cleaning as want to clean where the dirt is. If the spots are easily seen as distinct dark shapes when lunar viewing then more likely they are on the field lens since that is closer to the field stop. If they are more nebulous when observing and cause the view to blur then the eye lens might be the better culprit.

In any event, before doing any "aggressive" cleaning, very important to ensure all other dirt and dust is off the lens as you do not want those particles scratching the coatings with an aggressive clean. I presume you are using a Q-Tip to clean the surface, which is fine. When a spot is stubborn to get off using a cleaning fluid or alcohol, it might mean that the spot is biological (airborne tree sap, pollen, etc.) and needs enzymes instead to loosen or dissolve it. So you can try using some of your own saliva for that. Just wet the Q-Tip, then place it on the lens holding it in place for 15 seconds or so. Reason for that is to let the enzymes do their work first. Actually, this is a good practice for stubborn spots when using a solvent also like alcohol. So after some set time then swipe it to see if the spot was removed. If not, just repeat a second time. When you let the solvent or enzymes sit on the lens surface for a bit of time, they will generally loosen the or dissolve the spot so no aggressive pressure is needed. If you do want to try some aggressive pressure, just do it with a single swipe. Multiple swipes may cause the removed spot to then be moved across the lens and whatever hard material that spot/dust is made of could scratch the optic. That is why it is recommended to only do one swipe then get a fresh Q-Tip or cloth.

If that works and you used saliva, then follow up the cleaning with alcohol or distilled water to get any remaining compounds from the saliva off.

Good luck!

Wow, this really helped a lot! Thank you very much for the advice.
Actually, I am always using a microfibre cloth with Baader wonder fluid for cleaning EPs. The 6mm is a pain to clean honestly, especially the the field lense (I am guessing that's the bottom one

)

So this method kind of got most of these spots out of the way, so I will just repeat the process. The first time, I had a feeling that after having the bulk of them removed, repeating the process got my lens dirty again, and I couldn't get it cleaned properly. I will report back once I repeat the process.
Thanks again William!

Posted: **Fri Apr 29, 2022 6:19 pm**

Good luck, hopefully you will be able to get it back into operating condition again.

TheSkySearchers

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