Another cleaning eyepieces thread

[dreamstation]

Now I understand that most people will tell you that you probably don't need to clean them, and I fully agree, but I had one particular eyepiece that had an unknown drop of residue right in the middle of the glass. Light from bright objects would scatter and it made the eyepiece very difficult to use. It is my most used eyepiece so something had to be done.

Having read pretty much every thread on this particular topic on both IIS and several other Astronomy forums as well as several 'how to' guides on what to do and what not to do, I decided to give it a go recently. My problem is, even after thoroughly researching the topic for several weeks psyching myself up to it, I've somehow managed to stuff it up.

I've managed to remove the residue that was causing the original problem quite successfully using some isopropanol and the eyepiece works well again in the telescope but inspecting the glass with the eyepiece in hand reveals a film of something else over the entire surface. It doesn't appear to affect it's use but it's really annoying me and I'd like to get to the bottom of it. It's almost as if the isopropanol has left behind some residue but I was under the impression it shouldn't do that.

Does anyone have any suggestions on what is going on? Thanks.

[RB]

James, I know this is going to sound strange but give Lens Pen a try.
http://www.lenspen.com/

Make sure it's the original and not a cheap fake imitation.

I use it on all my photo gear and also on my Tele Vue eyepieces.

RB

[ab1963]

use a blower on the eyepiece to get rid of anything that could scratch the coatings,breathe on it and gently wipe with a microfiber cloth,sorted.
i would never touch my ep's with a lens pen,the 2 times i have had to clean my most valuable ep that's how i have done it with absolutely no problems ,just do it when you really have to ,that's my 2 cents worth

[ausastronomer]

Hi James

While less cleaning the better is the normal generalisation applied to cleaning optics, it doesn't really apply to cleaning eyepieces. The frequency you need to clean your eyepieces is dependent on the specific eyepiece design, it's eye relief and each person who has used the eyepieces physiology. Some people generate a lot of natural eye lash oil and tear residue which combined with eyepieces having shorter eye relief can necessitate frequent cleaning to optimise the views.

Don't be scared to clean the eye lens of your eyepieces. Just make sure you do It carefully with the correct technique and materials. I use a blower bulb to remove loose residue then several cotton buds with 99% isopropyl alcohol. Using each bud for 1 gentle wipe.

Cheers
John B

[RB]

John is absolutely correct, don't be scared but if you do it using liquid, then use his method with 99% isopropyl alcohol.
I should have mentioned the use of a blower first or course.


Andrew I did say it was going to sound strange but believe me, The Lens Pen is perfect for optical cleaning especially in this situation where James states that it's "a film of something else over the entire surface."

I've used The Lens Pen on tens of thousands of dollars worth of equipment, from my Canon lenses and cameras right through to my EP collection.
It's never damaged anything and has always brought back that "showroom look" on all my optics.
Just make sure it's the "real McCoy" and not some cheap imitation.
There's a reason why it's so heavily imitated.

Cheers.
RB

[dreamstation]

Hey John. The method you described is exactly what I did except that I used each cotton bud twice, once on each side. I'm really at a loss as to what the 'film' of residue left on the glass is or where it came from. It's either come out of the alcohol which I thought was highly unlikely or it's the original drop of residue spread all over the glass..? Maybe I should give it another going over to see if it comes off. I'm scared!



Thanks for the suggestion. I'll have a read!

[ausastronomer]

Hi James,

Did you use cotton buds or cotton balls? Cause if you used cotton balls I can tell you straight away what the residue is :)

Cheers,
John B

[dreamstation]

Hey John. I used the double ended cotton buds, not cotton balls!

[RB]

Can you post a photo of the problem James?

:)

[ausastronomer]

That's fine then. A lot of "cotton balls" are impregnated with perfume, or lanolin which dissolves into the isopropyl alcohol and then dries on your lens when the alcohol evaporates.

I only ever did that once and it was many years ago. My 8" mirror looked like a snail crawled over it continually for a month in every direction. It took a lot more isopropyl alcohol and lint free cotton to get it off. Never again. I have since sourced a good supply of lint free cotton which I use to clean my mirrors and larger optical surfaces and I use good quality double ended cotton buds for my eyepieces and binoculars.

Cheers
John B

[RB]

James listen to John B's advice, as you know he's very knowledgeable and a highly experienced observer and eyepiece expert.

I just wanted to show you what I do if I have to deal with basic smudges etc that aren't too excessive.
Here's an example I did tonight for you on my Meade ETX 90, (btw I know my secondary is off centre, that's why it was dirt cheap).
I haven't cleaned it in over 5 years and it had a smear right across the corrector.
A few quick wipe-overs with my lens-pen and it's back to that 'show-room' look.

Anyway, good luck with your cleaning.

RB

[dreamstation]

I will try and get something up over the weekend!



Oh don't worry, I'm all ears. John has been a tremendous help to me on several occasions since joining IIS and he probably doesn't even know it ;) There are a lot of very helpful people on here and I'm very thankful for their wisdom!

[dreamstation]

Here is a photo of the issue. The eyepiece is dirty as it has been used since cleaning but you can clearly see the residue dried on the glass. :shrug:

[dannat]

crap that's filthy, if you don't have alcohol handy [I find lens pen tend to dry fairly quickly] I often just use blue windex for my e's, but then again I tend to wipe them over fairly regularly
cotton bud are fine, I avoid lens tissue, I find it too abrasive if you don't use it soaked
I also have a large box of zeiss lens cleaning wipes, they are like KFC moist towelettes, in mini foil packs -they work great

[jeelan]

Just on the note of cleaning lenses, does anyone know if the spray on aeroguard can hurt lens coatings?

the other day I was out with a group of friends and one of them was rubbing aeroguard all over himself by spraying it into this cupped hands first - I was wary of him handling lenses after that......

cheers
Jeelan

[dannat]

aergogard i'd hazard a guess at YES, it has to have some chemical -who knows how it could interact with the coating

dare I bring up peter [exfso] exp with his TAk scope -had to be sent back to japan due to insect repellant

[croweater]

Some cleaning info here http://www.televue.com/engine/TV3b_page.asp?id=103 Cheers Richard

[ausastronomer]

That's asking for trouble IMO. Either spray it on directly, or wash your hands thoroughly afterwards. I am the same when I go fishing. Aerogard sprayed on directly because you don't want it on the bait, or terminal tackle. Unfortunately it's hard to know what people have on their hands when they wander up to your telescope 1/2 way through the night. That having been said I would expect that a diligent experienced observer would know not to put insect repellant on their hands when they are going to be handling optics or eyepieces.

Cheers
John B

[RB]

Aerogaurd is a big no-no around my scopes.
There's no way I'd let anyone using or spraying aerogaurd anywhere near my TOA's and eyepieces.
Like John and Daniel said it's a hazard and asking for trouble.
Daniel, I still cringe when I think about what happened to Peter's (Exfso) TOA 130 at that star party and have always been cautious ever since.

If you must use it yourself then just use a roll on repellent sparingly and make sure you don't have it on your hands or near your eyes when observing.

:thumbsup:

RB

[jeelan]

Pretty emphatic responses!! thanks for clearing that up....

cheers
Jeelan

[Don Pensack]

Don't spray any cleaner directly on the lens as it could creep around the edges of the lens and get inside.
Instead, spray your cleaner on the q-tip and use the wet q-tip to clean the glass.
Make a spiral circle from center to edge.
Flip the q-tip over to the dry end and repeat, mopping up the fluid left by the wet end.
Repeat with a second q-tip with wet end and dry end.
Grab a 3rd q-tip and making a swipe from edge to just past center on a radial line, wipe back and forth as you rotate the eyepiece under the q-tip.
After about one revolution of the eyepiece, flip the q-tip over and continue for at least one more rotation of the eyepiece.

If the eyepiece is clean at this point, you're done.
But if you see spots, get the eyepiece lens wet with a solvent-carrying q-tip again only this time, mop the eyepiece dry and clean with a new, unused, soft microfiber cloth, and go around the entire lens until there are no spots.

Unless you're cleaning a filthy eyepiece, I doubt you'll ever get past the q-tip cleaning.

[Don Pensack]

Your secondary isn't off center, the glue holding the secondary baffle to the glass has softened and allowed the baffle to slide sideways from the secondary.
You can unscrew the from cell of the scope and pull the baffle off and re-cement it in the correct place.
Use a glue that won't liquify when it gets hot as the scope sits in the sun for an hour or two.

[RB]

Thank you for the info Don.
Much appreciated.

RB

:cheers:

[dreamstation]

Does anyone have any suggestions on what went wrong with my previous cleaning attempt? I posted a picture on the previous page in case anyone missed it.

It seems the general consensus is to use cotton buds with some form of cleaner, alcohol, etc which is exactly what I did. It's just that it left behind an almighty film of crap that almost looks worse than the original problem I was trying to remove. Perhaps I was too generous with the alcohol?

Thanks a lot to everyone who has offered advice. Appreciate it!

[Don Pensack]

If the alcohol was pure and the cotton balls didn't have lanolin added, then whatever was on the eyepiece was partially put into solution and smeared around the lens.
It wouldn't be odd to have to clean something 3 or 4 times to get rid of all the residue.
I could regale you with stories about mascara and acidic fingerprints!

[Wavytone]

What was the cleaner, exactly ? The point is that most cleaners sold for domestic uses contain variety of assorted gunks - traces of lanolin, parafin and many more are not uncommon.

Some exceptions I've found you can rely on are distilled water, the stuff sold by Astro shops to clean optics, or Windex glass cleaner. The various alcohols sold by chemists on the other hand contain traces of something oily. And acetone as sold for nail polish remover contains lanolin, while the "pure" acetone sold at Bunnings leaves a white waxy residue, also.

Sydney tap water doesn't do a bad job either.

[dreamstation]

I used Isopropyl Alcohol. I believe the brand was Diggers. It said it contained 100% Isopropanol on the label which from my understanding should be fine. It may be as Don said above in that the alcohol has diluted whatever the original residue was and I've just spread it around the eyepiece. Another cleaning may be in order but I had enough fear doing the first one. I'm terrified of scratching the glass!

[gaseous]

Hi James, I also used the Diggers brand alcohol on my eps over the weekend, using the cotton bud technique outlined above, and got the same sort of residue as you (although perhaps not as bad as yours!). I was surprised at the amount of residue also, as the ep wasn't particularly grotty to begin with. After numerous attempts with the cotton buds to clean it up, I had to resort to a gentle wipe with a microfibre cloth to get it sparkling again. Not sure if it's something in the liquid (which seems unlikely), or something left over in the cotton bud manufacturing process which the alcohol dissolves/spreads on contact.

[75BC]

I may be mistaken but when I was looking for Isopropanol a while ago I saw the Diggers brand at Bunnings and I thought the label said it was only about 70% which would not be suitable.

I ended up getting some 99.8% from Jaycar Electronics.

[gaseous]

Yeah, possibly mistaken - I've got my bottle of Diggers here: 100% isopropanol. I (foolishly) tried Isocol a while ago, and later read that it's only 64% isopropanol. It leaves the same crappy residue as the good stuff though. Must be the cotton buds....

[dreamstation]

Just checked mine last night and it does say 100% Isopropanol as you said.

[75BC]

Quite happily mistaken on that one. I know from experience how (and not just with astronomy equipment) using the wrong stuff can turn an easily cleaned blemish into a mess.

Funny thing was when I bought mine from Jaycar the guy asked me what I wanted it for and when I told him he tried to convince me not to use it saying IPA shouldn’t be used on glass.

[dreamstation]

Never did get around to updating this thread. I cleaned the eyepiece again using Don's advice with better results. There is still a light film of something on the glass but it's a lot cleaner than it was before. It doesn't seem to affect viewing through the eyepiece but it still bugs me.

[bigjoe]

Yep has to be 100%.
Made the same mistake myself once!
bigjoe

[Wilso]

I use the same Diggers 100 %isopropyl alcohol but have gone the other way by diluting it down by 10% rainwater.
Get fantastic results. No residue, crystal clear.

[RobAB]

Yes Darren

I take 99% isopropanol and dilute it with 50% distilled water. This is because I find that pure isopropanol evaporates too quickly. Before you get a chance to mop it up with a cotton bud, it evaporates, leaving the dissolved residue behind on the eyepiece.

[Stonius]

There is something about coated optics that shows up the slightest bits of oil, far more than uncoated glass. So at the point at which you would call normal glass 'clean' and be content, coated optics still look like crap, even though the performance is the same optically at the same level of clean. I think it is something similar to the effect of thin layers of oil on water. I found this out when I had two different polariser filters on two different lenses that I was shooting for a skyshow. One was *so hard to keep clean, and it was the expensive Hoya one. It was because the coatings showed up the oils, whereas the other didn't but it made no difference to the image.

Cheers

Markus