Marks on my EP lens - not cleaning off

[Bart]

I noticed marks on my 14mm and went to clean it tonight. Blew off any loose material, brushed, blew, then gently wiped with cleaning fluid and microfibre. It's definitely cleaner, but not clean. I can still make out marks. I don't want to use much elbow grease. Cleaned a couple of other EPs and they look immaculate. I know it was left in the rain once (ES = waterproof???). Anyone have any ideas, please? Thanks

Barry

[Moonshane]

on the rare occasions I clean my optics, I've had stubborn grease that needed acetone (which I use or isopropyl alcohol) to remove. beware of any plastic bits with acetone though.

[E621Keith]

What cleaning fluid did you use?

Baader Optical Wonder fluid is highly recommended for telescope lenses. It's performs better than many cheap camera lens cleaner (like those sold in Jessops).

However don't clean it unless it's absolutely necessary. Over cleaning can do more damage than good and you may accidentally scratching the lens.

[Bart]

Thanks Moonshane

Forgot I had IPA in the garage. Tried it and have decided that either the coatings are gone or there's something (mould) on the inside of the top lens. Will try acetone but fear the worst. Will have to see how noticeabe it is while viewing DSOs, hope not too bad.

Thanks

Barry

Hope this doesn't mean I'll have to treat myself to the 100* 14mm...........

[alan potts]

Hi Bart,

I have not seen posts from you for a while, too many clear nights? Which eyepiece have you had a problem with?

Start saving, you know now it's in print you want the 14mm and will have to buy one.

Alan.

[Bart]

Keith, thanks, the fluid I was using isn't the best probably. Did try IPA and fear the worst.

Alan, don't know why I haven't been too active recently. The total cloud cover for the last 5_6 weeks had dented my astro mojo! Thur night was great. Got skysafari on the phone, found a couple of new galaxies, got two jovian moon shadow transits and the sight of two moons just off Jupiters disc with a shadow and the GRS with good seeing was absolutely superb. Work suffered, I felt, the following day.

You shouldn't be egging me on to buy more EPs, I have only just recovered from a buying frenzy in the Autumn!

Barry

[Moonshane]

eyepiece coatings are pretty hard. unless you physically scrape them it's unlikely they are damaged. I bet it will come off with acetone.

[johnnyha]

There is not a chemical made that can beat the glass cleaning power of human saliva or "spit".

[Moonshane]

that may be true but I suspect that spit also contains many things adored by fungal spores?