What to do after a Dew attack

[matthasboldlygone]

All started well tonight, been out for an hour and half or so but the temperature dropped quickly and everything dewed up at around 1am, fuzzy views, dripping off the tripod and tube.

Bought it all back inside, but do I now need to clean everything. If water has condensed on the lenses and now evaporated will it have left noticeable residue?

I have a refractor and can wipe down the outside of the big lens at the front, I can maybe get to the mirror on the diagonal, but what about the insides and bits I maybe can't easily reach?

I hoping the eyepieces are somewhat sealed so just cleaning the outside will be ok?

What cleaning equipment do people use, and anything I should avoid?

Cheers 🛀

[RT65CB-SWL]

Hi Matt.

I usually let my 'kit' dry out naturally with everything uncapped and make sure objective cell is pointing down, whilst I get some sleep/shut eye. When I am awake, check everything, and blow off the optical surfaces with a rocket blower and brush off with a soft camel hair brush. Then clean with some Baader Optical Wonder Fluid and cloth: https://www.firstlightoptics.com/astronomy-optics-cleaning-protection/baader-optical-wonder-set-cleaning-fluid-and-cloth.html

Don't do it straight away. 

[matthasboldlygone]

7 hours ago, Philip R said:

Hi Matt.

I usually let my 'kit' dry out naturally with everything uncapped and make sure objective cell is pointing down, whilst I get some sleep/shut eye. When I am awake, check everything, and blow off the optical surfaces with a rocket blower and brush off with a soft camel hair brush. Then clean with some Baader Optical Wonder Fluid and cloth: https://www.firstlightoptics.com/astronomy-optics-cleaning-protection/baader-optical-wonder-set-cleaning-fluid-and-cloth.html

Don't do it straight away. 

Thanks Philip, I've given it a good blow and a gentle brush (not sure it's camel hair but very soft). Looks cleanish I guess.

£16 for 100ml 😱, I know nothing in this hobby is going to be cheap, I guess it comes in a presentation box which is nice. I see it for £11 without the box. Looked up the composition and it doesn't seem to contain anything 'wonder'. Reading their own advice they suggest avoid cleaning except finger prints and pollen, don't worry about a few specs or dust.

Ready to try again on the next clear night due in two weeks, if I find a mushroom growing inside it I'll rethink 👍

Edited July 11, 2020 by matthasboldlygone

[RT65CB-SWL]

6 hours ago, matthasboldlygone said:

Thanks Philip, I've given it a good blow and a gentle brush (not sure it's camel hair but very soft). Looks cleanish I guess.

£16 for 100ml 😱, I know nothing in this hobby is going to be cheap, I guess it comes in a presentation box which is nice. I see it for £11 without the box. Looked up the composition and it doesn't seem to contain anything 'wonder'. Reading their own advice they suggest avoid cleaning except finger prints and pollen, don't worry about a few specs or dust.

Ready to try again on the next clear night due in two weeks 👍

You only need one small squirt (on the cloth) as a little goes a long way... I purchased a bottle and cloth several years ago and I reckon I have used one-eighth (1/8) of the liquid. I have used it on cleaning my 'scopes, e/p's., filters, binoculars, camera lenses, camera display, specs, tablet, phone, laptop display screen, and interior mirror of vehicle. etc. Don't use the same cloth on different articles. For cleaning e/p's and filters, I use one squirt in a plastic milk bottle lid and a 'Q-tip'. 

There are plenty of YouTube, etc., showing you how to clean delicate optics. 

Edited July 11, 2020 by Philip R

[Ricochet]

10 hours ago, matthasboldlygone said:

anything I should avoid?

Yes, you should avoid touching the optics. Let them dry naturally, don't wipe them. Mirrors have the most fragile coatings, eyepieces the hardest (on the exterior lens faces at least). Unless you get some sort of organic matter on the objective it is usually best to leave it. If you ask most experienced astronomers when they last cleaned their telescope(s) the answer will usually be in years.

[jonathan]

In theory water droplets formed from the atmosphere should by definition be pure, although don't quote me on that.

[matthasboldlygone]

6 minutes ago, jonathan said:

In theory water droplets formed from the atmosphere should by definition be pure, although don't quote me on that.

Ooops, sorry 😛

Interesting idea, I'll do some more research. I guess it would collect dust and bits, but that would be collecting on the lens anyway.

[jonathan]

On 14/07/2020 at 22:40, matthasboldlygone said:

Ooops, sorry 😛

Interesting idea, I'll do some more research. I guess it would collect dust and bits, but that would be collecting on the lens anyway.

The water droplets may be (mostly) pure, however as you say there might be dust on the surface that the water interacts with to create smears or water stains etc.  Also be wary of taking your scope outside if people are likely to be letting off fireworks, or if there's a forecast or chance of dust or sand particles being blown across from the Sahara or nearby fields (which might then fall onto your scope during the night).

Edited July 18, 2020 by jonathan