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Whuh??
Posted: Sat Feb 19, 2022 6:01 pm
by pakarinen
Was taking some pics of my 90 Mak in case I decided to sell it and noticed spots on the corrector. I don't know when that happened or what it is. I've never seen fungus and this looks like maybe something attacked the coating chemically.
Experts?
Thanks!
Re: Whuh??
Posted: Sat Feb 19, 2022 7:48 pm
by Lady Fraktor
A bit hard to tell from the size of the image but it is a possibility.
Could they be water spots on the inside of the corrector?
With close inspection can you tell if it is on the inside or outside?
If the outside it should not be fungus.
Re: Whuh??
Posted: Sun Feb 20, 2022 9:21 am
by John Baars
If it is on the inside, there should be no problem cleaning it.
Mark the position of the corrector like in the picture.
Unscrew the corrector.
Clean it with a mild soap and a scratchfree wet cloth. Don't go scrubbing.
Keep the cover on, because it is black you'll see every contamination.
Rinse with a wet cloth.
Dry with a scratchfree cloth.
Blow it dust-free
Screw the corrector back on and reposition according to the markers.
Ready! No collimation needed.
Try to work in a dust free environment. Because the background is black, you'll see every little spec of dust. Not that it matters for the image, but selling is another story.
Re: Whuh??
Posted: Sun Feb 20, 2022 3:09 pm
by pakarinen
They're on the front - maybe dew? I've never felt the need to use a dew heater, but maybe I should.
Is dishwashing soap too strong? I remember years ago that people were using distilled water and alcohol, but I think that was for primary mirrors.
Re: Whuh??
Posted: Sun Feb 20, 2022 5:28 pm
by Star Dad
I've used ORIGINAL Windex and ORIGINAL Bounty wipes as someone recommended to me. They do a great job and dries quickly. I have a Newt, and have learned that some Windex gets in behind the mirror on it's mount. So I make sure I wait a couple of hours to remount the mirror so I don't get streaks of droplets. You can also use Acetone if conditions are bad enough and then hit it with the Windex.
Re: Whuh??
Posted: Sun Feb 20, 2022 5:48 pm
by Lady Fraktor
Re: Whuh??
Posted: Sun Feb 20, 2022 5:59 pm
by Bigzmey
What Gabby says.
