Dew issues

[Ashen (Caleb)]

Just wondering if anyone gets dew problems on their primary or secondary mirror on an 8" Newtonian and how you solve them.

[AstralTraveller (David)]

Dew is a pita. Normally dew forms easily on the finder, a bit later on the secondary and only on the primary if things a re really bad (at least on a solid tube newt). Eyepieces can also dew but I tend to change them regularly and keep them in a warm place when not in use.

Two solutions. Move to a very, very dry place or fight the dew. A hair drier can be used to clear dew and keep the optic warm enough to prevent dew. That is cheap but clunky. I think most people end up having to buy heater straps and a controller.

[Startrek (Martin)]

Believe it or not I’ve had success using a pedestal fan blowing air constantly over my imaging rig all night ( 8” f5 Carbon Newt ) until the early hours.
The fan has to be running before dusk and the fan speed and distance to the rig has to right in order to avoid it affecting my PHD2 guiding.
I used this method a few times last year and it worked contrary to physics.
I do have a Kendrick heater bands wrapped around my guide scope, front and rear of the OTA as a back up too but didn’t need them switched on.
Obviously if dew is ridiculously heavy , I mean really heavy then my method would struggle but light to medium dewy nights no issues.
Cheers
Martin