SCTs and dew

[osbourne one-nil]

In somewhere as foot-rottingly damp and cold as Cumbria, is keeping dew off the corrector plate of an SCT, using a heated dew shield, 100% effective or would the best I could hope for be to hold it at bay for an hour or two?

 

[newbie alert]

I've always found dew bands pretty much 100% on my sct but I live down south not up't norf

[NGC 1502]

53 minutes ago, osbourne one-nil said:

In somewhere as foot-rottingly damp and cold as Cumbria, is keeping dew off the corrector plate of an SCT, using a heated dew shield, 100% effective or would the best I could hope for be to hold it at bay for an hour or two?

 

Unfortunately I don’t think any anti-dew measures can be 100% effective.  It’s a case of doing the best we can and hoping we keep the dew away for as long as possible, as you’ve already suggested.

For SCTs a long dew shield plus a low heat band around the corrector plate, and perhaps the occasional use of a 12v low heat gun may be successful in giving you long enough to enjoy a good session.

Possibly others may have further or better ways of helping this issue, so I’ll check back later to maybe learn something.

[Stu]

@osbourne one-nil I think the above says it all really. Best endeavours and all that. The hairdryer is a good option if things start to go south.

The only other thing you could try is wrapping the scope and dewshield in reflective matting. This may cut down on radiative cooling and slow the formation of dew.

[johninderby]

Dare I mention the Classical Cassegrain? 🤔

[Stu]

17 minutes ago, johninderby said:

Dare I mention the Classical Cassegrain? 🤔

Why, do you have one John? 😉🤣

[osbourne one-nil]

57 minutes ago, Stu said:

The only other thing you could try is wrapping the scope and dewshield in reflective matting. 

Or move back to Suffolk!

I've actually got a 6" RC which I bought for a bit of galaxy imaging. What I'm trying to do is get a setup which my youngest can have fun with and entertain himself with via an app while perhaps doubling up as an occasional imaging scope, so I have been wondering about one of the new Nexstar Evolutions. But thinking about it, I could just get an AZ GTI mount and let him use Sky Safari or something....