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Old 03-07-2019, 09:17 PM
Startrek (Martin)
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Join Date: Dec 2017
Location: Sydney
Posts: 2,603
Conditions looked great but PHD2 guiding poor

Last night I set up to image M17 as the forecast looked fantastic, no cloud , no moon , no wind and low Jetstream plus visually it looked really good , stars crystal clear and not twinkling
Located , framed and focused M17 at around 35 deg Alt , started PHD2 , auto selected guide star with SNR around 38 , calibrated ok , started guiding at 1.30 then went to 1.50 then 1.80 arc sec error with Dec graph looking ok but RA saw toothing around
Reduced Aggressiveness on RA from 75 to 60 and increased min mo from 0.20 to 0.30. Left Dec at 75
Fiddled a bit with Settings again but guiding didnít improve
Shutdown PHD2 and restarted , auto selected a guide star again with SNR around 41 , calibrated again with no issue , guiding started at 1.50 then 1.70 then 1.80
Fiddled with minor settings again and eventually settled around 1.50 to 1.70 which is not great
Iíve had my HEQ5 mount guiding at 1.20 to 1.30 arc sec error previously
Started my capture plan 70 x 2 minute subs with dithering and guiding took a long time to settle even on a low Dither. Sometimes didnít settle back to the error before the dither
I know I can send guide logs to PHD to evaluate the guiding but Iím thinking it was just ďseeing conditionsĒ last night that caused the guiding to be poor
I only had 2 bad subs ( star shape ) out of 70 with slight oval shaped stars, the rest were ok but not sharp and tight , a bit fuzzy
When I stacked the subs with my darks and processed the image it was terrible, a lot of noise , stars were not sharp etc.....
Then I decided to image Jupiter at around midnight with my 5 x powermate as I always do and could not even focus , the planet was just a fuzz ball , so shut down , packed up and went to bed
So forecasts and visual observations can be deceiving as it was suppose to be a great night but I had the worse night and a poor image
Did anyone else image in Sydney metro area last night ? Did you find imaging and guiding poor
Welcome any comments or advice
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Old 03-07-2019, 11:06 PM
Saturnine (Jeff)
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Join Date: Jul 2008
Location: Wollongong
Posts: 1,380
Yes , I can concur that though the predictions were offering good seeing, it turned out to be not so good after all. Was imaging Jupiter between about 11:00pm and 1:00am and seeing was at best 6 / 10 and was getting worse the later it got.
Did manage to get some half decent images from the stacks but wasn't guiding so can't compare guiding figures. The seeing is actually not too bad tonight and it is clear , for now , when cloud was forecast.
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