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Old 06-05-2022, 08:48 AM
Craig_
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Impact of jet stream on imaging

I was wondering what impact, if any, a strong jet stream has on imaging? It seems any time there is a strong jet stream forecast (like the below for tonight in Sydney) I seem to have loads of guiding issues. Not sure if that's coincidence or if it actually makes a difference? I'm imaging at 0.92" in case it matter (which it probably does.)
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Old 06-05-2022, 11:22 AM
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multiweb (Marc)
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I would say it does more often than not. You appreciate the seeing changes a lot more when you do planetary imaging. I can't say that I have seen anything workable in terms of focus when the jetstream forecast was over 80kts. You do get spells of steady air but generally it's consistently pretty bad. Even worse for long exposures doing deep sky imaging.
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Old 06-05-2022, 12:41 PM
Craig_
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I would say it does more often than not. You appreciate the seeing changes a lot more when you do planetary imaging. I can't say that I have seen anything workable in terms of focus when the jetstream forecast was over 80kts. You do get spells of steady air but generally it's consistently pretty bad. Even worse for long exposures doing deep sky imaging.
Thanks. Been pondering whether to head out and set up tonight. Looks good on most fronts except for that jetstream forecast..
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Old 06-05-2022, 01:03 PM
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floyd_2 (Dean)
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Same for me. Maybe we should put Sydney imaging to the vote for tonight lol. The jet stream forecast doesn't look promising. The weather gods are laughing at us. They give us clear skies for the first time in an eternity but make it impossible to guide / focus
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Old 06-05-2022, 04:51 PM
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mura_gadi (Steve)
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I wouldn't have thought that wind speed had much to do with it, last few layers often rock 100's kph all year round.

Have a look at conditions after your viewing and write notes on screen captures. Then you can write a bit about viewing on each one and after a while it will become a useful record of png's.

MG,
Ps.
I go RH and particulates from nullschool mostly, and check visually what's actually happening outside against nullschool regularly. Scoping night or not.

best to use the help file for use of the "Particulates" layers.
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Old 06-05-2022, 05:44 PM
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Camelopardalis (Dunk)
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Quote:
Originally Posted by floyd_2 View Post
Same for me. Maybe we should put Sydney imaging to the vote for tonight lol. The jet stream forecast doesn't look promising. The weather gods are laughing at us. They give us clear skies for the first time in an eternity but make it impossible to guide / focus
At least it’s not raining like it is up here

Image at a resolution where it doesn’t matter, i.e. low
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Old 06-05-2022, 08:41 PM
Startrek (Martin)
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Originally Posted by floyd_2 View Post
Same for me. Maybe we should put Sydney imaging to the vote for tonight lol. The jet stream forecast doesn't look promising. The weather gods are laughing at us. They give us clear skies for the first time in an eternity but make it impossible to guide / focus
I’m imaging in Sydney tonight at the moment and guiding is excellent at 0.50 arc sec total
I don’t take too much notice of the Jetstream as it fluctuates some much during an evening
If I judged whether Im going to image or not based on the jetstream I’d never do the hobby
Why not try first and then shutdown later if conditions deteriorate...
Humidity and dew is more of a problem when guiding, for me anyway
Maybe your imaging at super long focal lengths +2500mm , I image at 1000mm
and it’s been great tonight since 6.30pm
Take advantage of a beautiful clear night !!
Cheers
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Old 06-05-2022, 09:01 PM
Dave882 (David)
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Yep I’m noticing the same as Martin. Guiding quite comfortable between 0.45-0.55 rms at 2500mm. Taking some happy snaps of ngc4945… should come up nice!

From my experience the jet stream has a huge impact on planetary imaging but seems not so much on dso. Humidity, haze, smoke on the other hand is a killer.
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Old 07-05-2022, 07:04 AM
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Great feedback thanks everyone. I missed last night unfortunately - and it sounded like a perfect night too (I was too tired). I have my eye on this evening to get set up and have some EAA fun.
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