Quote:
Originally Posted by xa-coupe
I cant imagine the OTA getting frosty would do it any favours .. so well done on the insulation!
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Jeff, like Leon said, frost will not cause the scope damage.
The reason for the insulation around Phillip's scope is a different one. It is to help mitigate tube currents inside the closed tube OTA after setting up so you can start using the scope straight away without needing to wait for the scope to cool down. You will find more info on this here:
SCT and Maksutov insulative dewshield
This insulation of the OTA will also extend the time the corrector plate of both SCT's and Maks stays free from dew, but will not prevent it if conditions are very heavy with dew. However, there is a way to stop dew forming on the corrector plate that does not require heat. Heat causes more problems than it solves with scopes. Instead, a fan is installed inside the dewshield section in from of the corrector and positioned in such a way that it generates a vortex of air that whirls around inside the dewshield. This keeps the corrector dry, and will dry off dew that has started forming. No heat to distort the glass, no infrared interference, and no loss of energy into the tube of the OTA which does nothing but drain your batteries and introduce heat into the OTA - something that you had sought to remove from the OTA from the very start!
You will find more info on using a fan for dew control here:
SCT & Mak total dew control without heat - a solution!
This fan approach is not limited to just SCT's and Maks. It can be used with refractors too:
Refractor dew control WITHOUT heat - it is possible!
As for drying off frost from optics, I cannot say for certain right now yes or no as I have not have had my scopes subjected to conditions that would see frost form since starting with using fans. But I do have my suspicions that it will after seeing frost form one night when the breeze stopped, and then sublime when the breeze started up again. Remember professional observatories do not use heat to keep their optics dry from dew or frost. They cannot afford to have their optics be subjected to heat and the mass of complications that heat creates with it.
Alex.