[iceman (Mike)]

Hi all.

My primary and secondary are getting horribly dewed up lately with the scope pointing up for long periods while imaging Jupiter.

With my 10" scope, I was able to leave the fan running while imaging, which prevented dew from forming (and no vibrations or image degredation) - but with the 12", the fan is mounted differently (directly to the mirror cell) and it's introducing vibrations and degrading the image quality, which means I have to turn the fan off when I start imaging.. therefore, dew starts forming, I lose transparency, image quality degrades.

Anthony (bird) has solved this by cutting "trap doors" at the bottom end near the mirror, and one under the focuser for access to the secondary. When he starts dewing up, he can open the door and use the hairdryer to dry up the dew and reduce the fogging up.

So I want to do the same.

How should I do this? What's the best method and tools?

Thanks