Quote:
Originally Posted by Paul Haese
If I did not use a dew heater of both scopes I would not get any imaging done. My site has very high dew. Dew forms nearly every night. If you don't have dew control you dew up very quickly.
Seeing in the dome seems ok to me. The shutter opening is quite wide so that probably alleviates the thermals to some extent. The shape of the scope dome being a ball on the ground with no walls also probably helps control dome currents. The images I have produced with the RC12 in the dome seem sharp enough to me and not really affected by dome thermals. I could be wrong I suppose.
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thanks Paul. there is no arguing - you are getting very good results. I have no feel for the effects of domes (or other enclosures), but it seemed to me that it might be possible to improve resolution by a little bit if one could sort out what was damaging it in the first place. I also have trouble with dew, but have generally been able to image using only a low power heater in the airstream on the back of the mirror (about 0.4C increase in air temperature). It has always worried me that I can spend hours getting my planetary scope mirror down to ambient to maximise resolution - but for DSO it is necessary to heat the mirror up!
We can always be wrong
, but these forums can provide many well informed opinions to challenge ideas, so appreciate your feedback.
Quote:
Originally Posted by clive milne
Hi Ray,
The figures I have read in separate professional publications range between 2.5 to 3m/s .... and curiously, it has been stated that disruption of the boundary layer is best achieved when the airflow is directed horizontally across the face of the optic.
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Thanks Clive. will give it a try.
regards Ray