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What damage can be done cleaning eyepiece lens


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Hi. as topic title asks. I've had to clean a recently aquired eyepiece lens, the eye glass part., because it appeared to have a marking on it like a thumb print. When I cleaned it off using breath and micro fibre cloth in very gentle circular motion I managed to shift most of it. I left some at the very edge.

When I pointed it at the double cluster last night I noticed s very pronounced stretching effect around the entire view from maybe 40% out to the edge. Getting worse as it got to the edge. Odd thing is I pointed it at other targets layer in the night and didn't really notice anything but I'm guessing the vast amount of stars in the double would show up any eyepiece problems more. I Wonder if i damaged the eyepiece? Is hard to see how even very light scratches would introduce coma hence the post.

Could My scope be to fast for this eyepiece? Should be good quality. Could the Mark on the eyepiece have been something sinister? Looked like dew that wasn't evaporating or a residue Mark of some kind.

Edited by Stargazing00
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It I doubt that you damaged the eyepiece with gentle rubbing. Is the "stretching" all in the same direction, i.e. left-right, or is it radial from the centre? What is the coating looking like, rubbed off in places or nicely coated all over? Is the lens new or S/H? What is the lens?

Scratches don't produce coma either. They just scatter light perpendicular to the direction of the scratch.

Nigel

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Some eyepiece coating is stronger than other, most will survive cleaning without any problem, but a few bad one will fail. I used to use Eclipse to clean my eyepieces, but when I tried to clean my Celestron X-cel, the coating came straight off. After that I stopped cleaning my eyepieces using contact methods. I'd only clean them if it's absolutely necessary (i.e. fungus or other biological contaminant that may lead to fungus).

If you think your scope may be too fast for the eyepiece, put a barlow in there. If that doesn't reduce the problem then it's probably damage caused by cleaning. However, if the barlow improved the field sharpness, your scope is probably too fast for the eyepiece.

Edited by E621Keith
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I once new a bloke who was cleaning his eye pieces in the kitchen sink. as he was drying one with a hair dryer it slipped from his grasp. As he tried in vane to catch the e.p. he hit his forehead on the kitchen counter and stumbled backwards. now it just so happened that his wife was cooking dinner at the time and as he stumbled he knocked the chip pan from the stove causing the timber cupboards to catch fire. panicing his wife ran and called the fire brigade who were not too happy to see that he had put the fire out wasting their precious time which they spent 30 minutes making sure they understood the severity of wasting there time. this all happened in a small outback town in NSW Australia. Being a small town they only had one fire engine which was tied up whilst an electrical fire started in one of the shops in the main street. being that this town was built in the 1800's, the buildings were all timber framed so the fire spread quickly raizing half the town to the ground before the one engine could get it under control. So I guess the answer to your question is quite a bit.

OK, you got me, he wasn't cleaning his ep's, he was cleaning his mirror ;)

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Should be fine, are you sure your not being paranoid, my orion eyepieces degrade the image at the edge of the lenses' (this is normal), just make sure you dont get grit on them to rub in or you'l tear a hole in the space-time continuum & dr. who isn't real!

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Taken from "Turn Left at Orion"

...How to clean your lens.

Step one: Don't do it. Period. No step two required. If you still feel you need to clean your lens, our best recommendation is: don't. If the lens really needs it, the safest answer is still: don't...

Which made me laugh, but I have of course ignored that advice and cleaned fingerprints off with a spectacle cleaning cloth and the lens was fine. Mind you it was the stock (garbage) eyepiece that came with the scope, I could rub that lens clean with sandpaper, it might even improve the view a little.

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I clean mine if they need it. Tele Vue's website has perfectly readable instructions on how to do it which work fine. I use IPA and cotton buds to clean mine. (edit: obviously use a puffer first to clean off every single spec of dust, it's the dust the scratches your lens, nothing else)

this eyepiece was rubbish by the way, so I just gave it back to the guy. no harm no foul.

Edited by Stargazing00
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  • 3 weeks later...

I allways put mine in the dishwasher, but beware don't ever put your eyepieces in the tumble drier to dry them , I did that once and my 21 mm ethos shrunk , it's now the size of a 21 mm plossl. ;-)

 

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