How do I solve this problem with my scope?

[KE400]

Hi

I have been lucky enough to be out the last 2 nights trying to image Jupiter. I have noticed what looks like to me what could be a BIG problem with my scope, (hope not!). I have the Celestron C9.25 OTA first of all, the problem is that there looks to be some kind of either dirt or dried moisture on either the lens or the end glass/plastic bit of the OTA.

I only can notice this when using a barlow lens when the markings become aparent, (I have tried the 3 barlows that I have so it's not one of those specifically)?! Could this be some small particles of dirt or something?? I tried taking screen shots of the problem and hopefully you can see what it is with these attatchments?

Can someone help me as to how to either fix this problem, ie, what is it? How do I fix it or what needs cleaning and how do I do it correctly and with what? Or indeed, can this be sorted or is it goosed?

Help Please.....................thanks for looking

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[Merlin66]

Kevin,

I'm sorry to say your telescope has had it! It will never work properly again....

I can be kind, and take it of your hands for say 50gbp but only if you can deliver it to Belgium.

Sad news.......

Only joking Olly!!!

The scope is in perfect working order! A great scope...

The issue isn't with the barlows either....what you're seeing are just a couple of "dust bunnies" caused by dust particles ON THE CAMERA sensor cover.

Remove the camera and use a blower to dislodge them - as easy as that.

HTH

[KE400]

Thanks Merlin, I will try it, would I be ok using a hair dryer as the "blower" because I don't have a cold air one?

Liked the 1st bit of your reply I nearly fell off my chair thinking it was goosed haha, phew!!!

[Merlin66]

Buy one of those photographic pump Rocket blaster blowers....you're going to need it in the future.......

[KE400]

I've noticed that the IR filter that I have attached to the cam has specs of dust on, just tried to blow them off but they aren't budging, is there some kind of special way to clean these filters? I take it that it's not a simple case of giving it a wipe with something?

[Merlin66]

If you take extreme care, the folded edge of a paper kichen towel can sometime just "flick" them off....I use the isopropyl alcohol mix for cleaning spectacles - just a small spray on the folded corner...a careful wipe and then a dry folded corner does the clean up.

HTH

[KE400]

Thanks, I think I'll go and buy some specs lens cleaner.

[themos]

I cleaned my webcam sensor with a Q-Tip sprayed with Optical Wonder fluid. Just used it like a brush, then a "rocket" air-blower for quick dry. Worked a treat.

[themos]

spec lens cleaner? No. they're not up to the job.

[michael.h.f.wilkinson]

spec lens cleaner? No. they're not up to the job.

Depending very much on the composition; some are fine, some less so. Just like the optical microfibre cloths. Some opticians provide really good cloths, others are downright bad. Buying stuff from the likes of Baader ensures you get the good stuff.

[themos]

by the way, how do you clean microfibre cloths? Mine is more likely to make things worse by now. Do I just bin it?

[michael.h.f.wilkinson]

by the way, how do you clean microfibre cloths? Mine is more likely to make things worse by now. Do I just bin it?

After a while, I bin it. I get good ones for free with my specs , so do not worry about binning them from time to time.

[sabana]

Yeh bin the cloths. Not worth mucking up your lenses.

[Merlin66]

Guys,

I wasn't talking about the spectacle cleaning clothes...I think they are not very good - even for cleaning spectacles.

I was talking about the small spray pump the optician normally gives you...this contains an isopropyl alcohol/ distilled water mix. It works very well with clean paper kitchen towels....

Just my 0.02euro.

[michael.h.f.wilkinson]

Guys,

I wasn't talking about the spectacle cleaning clothes...I think they are not very good - even for cleaning spectacles.

I was talking about the small spray pump the optician normally gives you...this contains an isopropyl alcohol/ distilled water mix. It works very well with clean paper kitchen towels....

Just my 0.02euro.

That mixture is OK, but I do not like using kitchen towels for two reasons: (i) there is no guarantee that they do not contain harder fibres, (ii) some types tend to shed fibres as well.

There may be a type that works well on both counts, but the missus just buys whatever is on offer, and if I buy my own they WILL end up being used in kitchen duties, so there goes my stockpile.

[Merlin66]

The unbleached, no-frills kitchen towels are very good!

I'd consider tissues if I could be assured they are 100% OK - no lanolin etc additives...(I did see the other thread where Keenex claim the 2 ply tissues have not changed in fifty years.....)

[michael.h.f.wilkinson]

The unbleached, no-frills kitchen towels are very good!

I'd consider tissues if I could be assured they are 100% OK - no lanolin etc additives...(I did see the other thread where Keenex claim the 2 ply tissues have not changed in fifty years.....)

My wife likes them with frills and bleached, so maybe if I stash some unbleached, unfrilled ones they will stay put

[KE400]

Thanks for all the input guys,

Just been to T*sco's and bought some decent lens cleaning kits from their optician. Got some good cloth's too and have just cleaned the offending objects! They have come up great, just need to get back out and see through the kit if it's done the trick.

Just while we are on the subject of cleaning lenses, what is used to clean the end of the scope? Is it the same stuff or is there something completely different?

Thanks

[Capricorn]

Glad someone has identified the problem as all I could say is that the front plate isn't in or near the object plane so you will not be seeing anything on that when viewing or imaging.

The front plates of SCT's tend to be quite substantial and the cloths and fliud you have should be fine on it. I actually think that most of the weight of an SCT is that corrector plate. It isn't small and not overly delicate either. Normal, sensible care when cleaning should be fine.

[KE400]

Thanks Capricorn, I have given the front plate a clean too, along with the barlows.

[michael.h.f.wilkinson]

SCT front plates are quite thin, especially compared to the meniscus lens of a Maksutov. They can be cleaned easily. Most of the weight of the SCT is at the rear, in the mirror and its mount.

[KE400]

Just a quick update on this problem I had.

As predicted by the very helpful people on here, after cleaning everything with the lens cleaner and correct cloth, the problem is no more.

Amazing that specs of dust on the lens was the problem, these instruments are very sensitive.

Thanks all for your input and help.