Cleaning advice.

I did a quick search on the site for advice on cleaning,
specifically the main lens on my ETX-125.

Someone posted this excellent walk through by the famous Dr. Clay:

www.arksky.org/asoclean.htm

but it's after making me take stock and ask myself the question,
''do I really need to clean this? Would a light dusting not be best''

Here it is:
www.flickr.com/photo_zoom.gne?id=2150994927&size=o

I understand that every time an optical surface is 'cleaned' you
microscopically reduce it's effectiveness.

Worse still for UHTC optical surfaces as this is (as the name says) a
coating and a very delicate one at that.

To be honest, I'd prefer to live with dust if it means the quality
of the light transmission is near enough to the quality it was when I
got the scope (a year ago).

Does anyone have any idea just how bad the dust has to be
so that cleaning will make more of an improvement at the loss of some
of the UHTC quality?

Cheers,

The dust has to be pretty bad before it will have a noticable effect on the image. That said, you should keep the lens or corrector plate as clean as possible by giving it a regular dusting with a squirt of compressed air (ideally) and/or a soft lens brush. The real killer for lenses is pollen, which can become firmly stuck to the lens if left for a while. Pollen is tough stuff to shift once it becomes moist with condensation/dew, and may need washing with warm water and a little soap to remove it.

So your plan of attack should be... Blow... Brush... Wash (if necessary) in that order.

Phil.

PS - you can get cans of compressed air from www.radionics.ie or from www.farnellinone.ie

My understanding is that if you look after your equipment well that dust on the lens should not be a problem for many many years (and even then it wont be a big problem).

If it aint broken...dont try and fix it.

Frank,
Cleaning what you have there will not improve the image you see through the scope.
Iif you are going to clean the corrector then use iso-propyl alcohol and cotton swabs, do not soak the corrector as the liquid will get into the cell and make things alot worse for you.
Cleaning lenses is not so bad, cleaning mirrors is alot more dangerous, just be careful that you don't scratch it.

use iso-propyl alcohol and cotton swabs

Wooooaaahh! Hold it there Dave, don't cotton swabs have very small fibre glass particles in them? I was always told to stay away form cotton swabs as they will tiny scratches your plate....

I remember some years ago I had a 6" mirrir, and used cotton swabs to clean it, and indeed it did leave some small scratches behind, maybe just cleaning with the fluid and a good old lens cleaning cloth will do instead?

Keith..

Yep Keith's bang on don't use ordinary cotton wool. Go to the pharmacy and ask for surgical grade cotton wool.

Frank, I'd just be inclined to dust off that lens with a good quality camel hair brush. You'll get one from a good camera shop. I found the celestron 'lens pen' very good too.

It certainly doesn't need washing.

Also if you do use isopropyl alchohol you should mix with distilled water in the ratio of about 60parts water/40parts alchohol.