Re: What's the effect of imaging through jet stream?


Glenn
 

cytan,

I generally have poor local seeing, but I am amazed at the variation that is possible. On good nights, guiding with my Mach1 (last generation) is around 0.3-0.4 arc seconds and the resulting HFD of the subframes is in the 2-3 range. On bad nights, particularly when the jet stream is a factor, guiding is 1.5 arc seconds or worse and the HFD is much higher. On the worst night in memory, my HFD was 10+! I thought there was something wrong with my optics—the stars looked like giant snowballs and refocusing did not improve them. But a couple of nights later, guiding and image quality had returned to normal. So in my experience the jet stream can significantly degrade both guiding and image quality. 

Regards,

Glenn

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