|
I would put it on the objective or the dewshield where the objective is.
On the main body does not make sense because 1. Its the objective you want slightly warmer to prevent dew not the body and 2. Tube currents are destructive to sharp imaging.
I have wondered how much thermal currents from the dew heaters in the tube of a refractor degrades the image given how the images sharpen up once the refractor (or other types of scopes for that matter) equalise in temperature.
I think though without having done extensive testing its likely that putting the dew strap on the body would create thermal currents which would degrade the images to some degree.
I can't say I have noticed this on my AP Honders but that has an oversized tube to remove tube currents so its not a good example.
I used to use those wrap around insulation blankets like used on car windscreens. You wrap that around the objective area at the beginning of the night and it would keep the scope dew free for almost all night most nights.
Greg.
|