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Condensation in an APO triplet?
Hi all, Bill here
Took my new scope out yesterday to the ASV dark site for some time with Eta Carina (fighting the glow from the Moon as well). It's a Sharpstar 107PH APO triplet. Next morning I noticed a layer of condensation on the lens - it was pretty dewy, so that's OK, but looking closely at it, I'm not certain it was on the outside of the lens. Of course, it's hard to tell just by looking, and I sure as hell wasn't going to touch it my my grubby paws! I left it in the sun for a half hour and it cleared nicely.
My question is: with an air-gapped triplet, is the gap open to the atmosphere, or is it sealed (in which case it should probably be filled with something like nitrogen, right)? Is this going to be a problem, or is it just something that happens and I can get around with some warming tape or something?
Any thoughts or advice are welcome.
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