Blue spots on objective lens

[StuartT]

I am seeing some spots on my objective. Hope you can see them on this image.

What are they? Do I need to worry about them? (I try to avoid ever cleaning optics - all I do is use a dust blower bulb occasionally)

Edited February 6, 2022 by StuartT

[StarryEyed]

Is the scope under warranty? if so send it in to have it checked out. 

[StuartT]

19 hours ago, StarryEyed said:

Is the scope under warranty? if so send it in to have it checked out. 

Yes, I bought the scope less than 12m ago. Do you think it's serious then? I really don't want to have to send it back!

[The Lazy Astronomer]

20 hours ago, StarryEyed said:

Is the scope under warranty? if so send it in to have it checked out. 

Woah, let's not jump straight into that!

1 hour ago, StuartT said:

Do you think it's serious then?

Unless it's damage to the coating or fungus growth, it's probably not serious. Fungus growth is very distinctive (spider web like patterns), so it should be possible to rule that out immediately.

I reckon your options are:

1. Attempt to clean it to see if the marks are removed

2. Contact FLO (or wherever you brought it from) for their assessment

3. Do nothing, provided you can determine it's not fungus growth or damage to the coating (this is likey the best option)

[paul mc c]

Personally I don't think it's anything to worry about, it looks like tiny dew spots nothing serious. 

[StarryEyed]

A 150mm objective is an expensive bit of glass if you don't know what your looking at. Talk to the supplier first before you do anything and follow their advice. If you follow their advise and its under warranty your covered. 

[mikeDnight]

Pretty sure they're dew spots. Doesn't look like anything to worry about and they may possibly disappear when cleaned. Even if they don't, they won't affect performance. I use the caloclean spray and cloth which is great and cheap.

[Carbon Brush]

Based on the photo - not a proper look - I think it is dew spots, nothing more.
It is not degrading the image and not doing harm to the lens.

At some point you will want to clean the objective. But no rush.
The time will come  when you get problems from pollen, bits off tress, wind blown sand, fly droppings, bird droppings, etc.

For cleaning lenses, I always uses Baader wonder fluid & their cloth. I have yet to do harm to anything.
Awful name but very effective stuff.
I always take a bottle and the cloth on holiday for cameras, binos, scope & specs.

My thought on first purchase was if it it does harm I am in a postion to say to the astro retailer....
You sold me this eyepiece/scope and I cleaned it using the fluid you sold me. Now it is wrecked.
What are YOU going to do to put things right?
If I said the speccyfluid/anyname/whatever has damaged a coating, then I am on much shakier ground.
Just an untested theory. Baader works well and has not (yet?) done harm.
There are plenty of other decent cleaners, with proven performance. It is very much a personal choice.

HTH, David.

[StuartT]

Thanks. I have Baader Wonder Fluid which is what I would use.

But from what you've all said, it sounds like it would be premature to clean it now (on the basis that cleaning should be as infrequent as reasonably possible)

Edited February 7, 2022 by StuartT

[jock1958]

As others have said I think dew spots are the culprits!!  My Tak FC-100DL lens had all sorts of crud on it,  I went through all sorts of mental anguish before cleaning it....a real nerve jangler for sure 😩

I bought two new Baader cloths and their wonder fluid and the lens was a minter after I'd finished.

One tip I got after lots of research is to divide the lens into quarters and clean one segment at a time, this seems to have worked for me, however others may disagree and have their own techniques 🤔

Check out my post below from a few years ago.

 

 

[Louis D]

They look like tree sap spots to me.  Do you observe near any trees?  Either way, they're completely innocuous.  Cleaning them off won't improve the view through the objective at all.

If you do feel an OCD need to clean them off, and alcohol based cleaners like BWF don't cut it, Roland Christian of AP telescopes has recommended in the past using a bit of saliva on the end of a clean fingertip.  The enzymes in the saliva will dissolve the tree sap and your fingerprints act like a harmless scrub pad.  After that, clean as normal.

I've never had issues with dew spots because dew is basically distilled water.  If it is carrying dissolved air pollution, that's a different matter.  Luckily, we don't have much air pollution in the part of Texas I live in, so no issues with dew leaving a residue.

[Highburymark]

If you’re concerned just clean one spot with your Baader fluid and a cotton bud. My bet is it would come straight off. As long as you’re not dragging any grit across the glass (ie blow and lightly brush the area first), you won’t do any harm. Telescope objectives are far more robust than they are sometimes made out to be.