Worth a clean?

[spaceman_spiff]

Hi all,

Basically I'm pretty sure what people will say (don't bother/not worth the risks) but I would like a second/third/nth opinion.

I have been using this telescope (SW Evostar 120) for about 4 years and it has seen quite a lot of action! Over this time it has accumulated all sorts of dust/grime/pollen/other stuff and the thought of cleaning it has been nagging me. I don't think the dirt is affecting my images (no difference with older pics) so I'm not losing sleep over it. 

I have gone over the lens with an air blower but I have done nothing else but I was thinking of using the Baader wonder fluid.

If this was your scope, what would you do???

Thanks! 

[Pete Presland]

I have used the Baader wonder fluid and it is very good, but i would probably leave well alone to be honest. If it is not affecting your images then why risk it also some of the dust/grime is probably on the inside as well.

[damnut]

That objective looks pristine. When the dust is an inch thick, as above, Baader wonder fluid & microfibre cloth!!

[spaceman_spiff]

That's what I thought.

Just wanted some confirmation

Thanks!

[Dave Lloyd]

What's the risk of affecting lens coatings?

[ronin]

I would clean it especially if there is pollen on the objective.

Then again I am happy cleaning glass of any sort, do it to my glasses several times a day, usually with the lower end of my shirt.

[F15Rules]

+1 for cleaning the lens. If my windscreen is covered with dust or flies, I clean it. Photos of lenses are notoriously bad at showing the real condition of glass, and your picture shows more of a reflection than anything else..if you think there is a fair amount of dust/debris on the lens then careful cleaning with BWF makes sense to me..why allow even more to accumulate, possibly making it more risky to clean later on when more "stuff" then has to be dealt with?

Just my perspective:-)

Dave

[spaceman_spiff]

Hmmm, now I am weighing things up again! It seems that opines are split down the middle.

In response to Dave Lloyd, I am not sure what the effect on the coatings would be. Does anyone know how soft they are on the SW Evo 120?

Also, when I am observing, I often tend to find a few new spots on the lenses that look like a clear residue. Not sure what they are but they have appeared on my glasses and it feels a bit sticky!   What are they???

[Scott]

I would clean it especially if there is pollen on the objective.

Then again I am happy cleaning glass of any sort, do it to my glasses several times a day, usually with the lower end of my shirt.

remind me not to let you near my 'scopes if your wearing a shirt.

[Alien 13]

I would clean it with a lens pen grime can harbour all sorts of nasties that want to eat your glass, if using any fluid be careful it doesnt creep to the edge it can destroy cemented optics.

Alan

[ollypenrice]

This is not the same as the mirror cleaning situation. Aluminium coated mirrors are soft. The coatings on refractor lenses are very hard. Because there are sometimes quite nasty things in the stuff which collects on your lens I would wipe it off fairly regularly. A lens cleaner and soft optical cloth will be fine. Wipe in circles and don't re-use the same bit of cloth.

I do mine several times a year without detriment.

Mirrors, however, I touch as infrequently as possible. I'm off to do the 20 inch as I write...

Olly

PS Half an hour later the truss Dob is done. I wait for a heatwave, such as we have now, and give the primary a good 'shower' in situ. The structure is ply and doesn't mind a wetting when it will be dry in half an hour or less anyway. Painless and, if taking it out gets it slightly cleaner, it also subjects it to more risks.

[spaceman_spiff]

 Thanks Olly!   

I was thinking of getting in some practice using the Baader wonder fluid with my glasses (obviously no using the lens cloth). After this (assuming an increase in confidence), I will have a go on the lens itself.

[ollypenrice]

There's nothing to it. One thing to remember, though, is to take no notice of residual surface effects that you might call 'smears,' tricks of the light which slightly resemble oil floating on water. These are almost impossible to avoid and have no effect whatever on the view. Ignore them. They only affect the miniscule fraction of the light which the lens is reflecting. You're interested in what goes through the lens. It's dust, pollun and chemical pollutants you're trying to remove.

Olly

[spaceman_spiff]

Hi all,

Thanks for the advice. I bought some Baader wonder fluid and a micro-fibre lens cloth (thanks FLO!) and had a go on the lens. I am very pleased with the results (see pic).

My main concern was that acids and other chemicals from pollen would damage the lens over time rather than directly diminish the view by obstructing light.

Dan