Cool down and dew control

[Gary70]

At the risk of joining the ever increasing idot section, and asking an old question.

Could someone please clear up a thought I have had for a while,

I understand the need to let a large Mak cool down to get optimum performance, and I understand how dew can ruin a good view, and the need for dew shields, but I have seen, but not purchased dew controllers and heat tapes;

And therein lies my question, would heating your scope to reduce dew warm it up so as to make real CD almost impossible?

Thanks

[stonemonkeylives]

Cooling you telescope down is there to prevent warmer air disrupting the air around your telescope, making it turbulent and deteriorate the seeing of the night sky. So its always best to let it cool down to the ambient temperature of the surrounding atmosphere. But because metal is much more efficient at dissipating heat than air is, it can get cooler than the surrounding air, where if there is moisture in the air, dew can form. So the the general idea is to keep the telescope at the same temperature as the surrounding air.

That's how I understand it to be anyway, but I'm sure someone more experienced than myself will correct me if I'm wrong

sent from Gherkin Muncher mk .III (commonly known as a Galaxy S2)

[M4lcs67]

I have a large SCT and also a dew controller and heatertape. Fitted and used correctly, this is a tried and tested method of keeping dew at bay. if used in conjunction with a dewsheild you will have even more protection, although in windy conditions this can become a problem as it can act like a sail, but as well as keeping dew at bay, it can act as a light shield as well, so it can have a double purpose.

Dew heater controllers are adjustable so you can apply just the right amount of heat for your particular conditions.

[Gary70]

I knew I could count on you guys, thanks

[jonathan]

Dew heater controllers are adjustable so you can apply just the right amount of heat for your particular conditions.

I've never quite worked out what 'just the right amount' is for my conditions... how can I tell when that is? I have tried it at low, half, high, and full power, but as every night is different it's almost impossible for me to tell which is the correct setting by trial and error. All I do know is that my scope will dew up eventually no matter what I do, typically within a couple of hours (which may coincide with my battery going flat!) As it's usually near to freezing when most of my observing seems to get done with the 8SE, I usually just whack the heating up to the max.