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Old 25-09-2020, 09:59 PM
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muletopia (Chris)
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M55 first gobula with qhy8l

After waiting for a long while for a clear night on Wednesday I captured this image.


20 2 minute frames, gain 0 offset 125
Melon 210 with field flatener, the image is uncropped..
,

When I installed the flatener I mounted a 700 mm fl external guide scope.
I think I will have to go back to Josha and have him mack an adapter to take tmy OAG unit.


Chris
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Old 26-09-2020, 05:46 AM
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PKay (Peter)
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Hi Chris

You certainly have captured all the star colours.
Try playing with saturation, and compare results with what others have achieved.
At each corner the stars are elongated (coma aberration) suggesting the field flattener needs attention. Check on it's back focus distance, and then to the sensor.

The stars in the centre look fine, so your guiding seems to be OK.

Well done!
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Old 26-09-2020, 06:08 AM
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Very nice image Peter, I love the intensity of the colour.
I do think there is a fairey in the site photo download section that turns up the saturation ...at least I always find my images much more saturated when I look the next day.
Also I showed your image to a friend and she loved it and asked if the stars were that co,our to which I replied...yes, and then went on to 3xplain the electro magnetic spectrum and how other creatures can see more colour than we can.
Those stars at the edge can be cropped out until you get a fix...I still have that problem on my 80mm if I don't crop. Keep up the great work.
Alex
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Old 26-09-2020, 09:54 PM
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muletopia (Chris)
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Thanks for the encouragement Peter & Alex.


Peter I take tour point on saturation, but another underlying factor came to mind.
The orignal image was processed

Debayer ,preprocess , stack in Nebulosity 4
Auto develop and colour in Startools
power stretch in Nebulosity.


Fro mast experience I developed a preference for stacking with Siril.


So in the process steps above the Neebulosity stacking was replaced with Siril stacking.


The Siril output is upside down in relation to the Neb output, I have no idea why.


The only comparable image I could find on this rorum wqas produced by atmos with his Mewlon 250. That has a focal length much the same as my Mewlon210.


I do think the attached image shows the benefit of the Siril stacking.
Another week of cloud coming so no experimentation with spacing.



Chris
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