How to put your optics away

At the end of the evening (even if it's just 2 hours) I'm likely to have at least a little dew, though sometimes not, on my EPs and/or SCT corrector and/or dob mirror.

I store all this in my garage. The EPs all go into a camera case, and the lids go on the scopes, but if I notice dew, I take the EPs (not the big scopes though) inside and wait for it to evaporate.

At best, with the scopes, I will not put the dust caps on until later (or if it is already late, then the next morning)...kind of a trade off between collecting dust and trapping dew.

Basically, I'm wondering what should I do?

It would be nice to pack it all up for the night and forget about it until next time, but I doubt that's possible...anybody got a good trick, like putting them all in front of the heater for a few minutes? anything I should be aware of as far as potential damage with such tricks?

How do you do it?

Thanks,
TomL

Tom,
My eye pieces go into an orion eyepiece case. In it I have a pack of silica gel dessicant (Opti-dry or some other brand). This dessicant is kept in recharged state so it is very absorbant. My eyepieces are kept in the case uncapped, so the moisture is removed by the silica pack efficiently. I shut the eyepiece case outdoors and do not open it indoors until several hours later. Cool EP's coming into a warmer moist indoors may result in condensation on the optical surfaces.

For the scope, the procedure is similar. The front objective is loosely capped and the scope put into a padded scope bag containing a similar dessicant pack. This case is zippered up outdoors and not opened indoors until several hours later. In addition, if you want to cap the objective tightly, you can even tape/velcro a dessicant pack onto the inner surface of the lens cap.

Do not wrap the scope with a towel. Reason: towel will absorb mositure (good) but will get mildew very quickly as moisture has no where to go (bad). Mildew is very bad if left unchecked as the common fungus Aspergillus niger is a prolific spore former. It's the towel in the gym bag scenario.

I would use a hair dryer with great care as some last resort. It's easy to over heat and thermally stress an optical element.

Lastly, something like a Kendrick system greatly reduces mositure on the optical surfaces during observation, thus minimizing the moisture issue. the important point is to take all possible measures to avoid condensation onto your optics. The condensate will carry and absorb all kinds of atmospheric pollutants and will in time attack your optical coatings.

Hope this helps, Ivan

The best thing I did for dew was move from Houston to SW Colorado.

Charlie

Tom,

Please see my website www.astroproproducts.com for information on my Opti-Dry product. It was designed specifically for the conditions you mention. It can be used with EP's, correctors, and all scopes and corrector plates.

Paul Atkinson
AstroPro Products