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During my recent lunar imaging sessions, I noticed that at least 3 different components to seeing as viewed on the computer screen as I watched an AVI being recorded.
The main component was a whole-of-image wavefront, where it was as if waves of long wavelength and low amplitude were washing over the scene. Small craters would have defined edges and then soften but never smear.
Then there were bouts of localised high frequency disturbances that would destroy all the fine detail for several seconds at a time.
The 3rd less frequent component was as if a heat plume had passed over the scene and the whole scene was washed out, a bit like applying a Gaussian Filter set to 50 or 100 across the whole frame. I looked up and there was no obvious source to this, e.g. my body accidentally passing near the open end of the OTA, a low jet flying over our house, etc.
So, when combined, the effect was that at times the seeing could be estimated at maybe 7/10 but with the other effects adding to that, it was reduced to maybe 5/10.
Cheers
Dennis
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