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Old 23-10-2020, 05:59 AM
Fernando
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M83

Dear all, for your comments and suggestions, regards, Fernando.


Camera: ZWO 075 MC Pro, -5C
L-Pro Filter
Mount: Mach1
SW Esprit 120 ED
100 x 3 minutes Lights + Dark + Flat Darks
Processed in PixInsight
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Old 23-10-2020, 06:39 AM
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oh wow, that's some great detail in the galaxy. Plenty of emission nebulae as well as dust lanes visible. I'll give this a go one day if the clouds clear, but my focal length is quite a bit shorter.

one thing it looks like you have some amp glow? affecting the lower part of the frame and some linear vertical artefacts generally. You might want to check your calibration frames, darks, flat etc.

EDIT i see you say using darks and flat darks but not flats? I use bias myself instead of flat darks, but thought flat darks need to be matched with flats to work
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Old 23-10-2020, 08:12 AM
Fernando
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[QUOTE=Robert_T;1497030]oh wow, that's some great detail in the galaxy. Plenty of emission nebulae as well as dust lanes visible. I'll give this a go one day if the clouds clear, but my focal length is quite a bit shorter.

one thing it looks like you have some amp glow? affecting the lower part of the frame and some linear vertical artefacts generally. You might want to check your calibration frames, darks, flat etc.

EDIT i see you say using darks and flat darks but not flats? I use bias myself instead of flat darks, but thought flat darks need to be matched with flats to work.



Thanks Robert,


I do have some amp glow with the ZWO071MC Pro. Still not able to avoid it in my light frames and/or fixing it totally during callibration; a final dynamic crop turns the image aestetically better (see attached). In the previous post, I made a mistake and posted the image still not cropped. By the way, I use darks, flats and dark flats and no bias. I will check the calibration frames, thanks.



Regards, Fernando
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Old 23-10-2020, 09:59 AM
Startrek (Martin)
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Fernando
Great image of M83 showing good detail in the spirals and nice star field
Noise floor is up a bit but trying to smear it or hide it would only affect your level of fine detail
Try reducing the blue bias a little bit and increase the red a little bit , just a suggestion
A great image just the same
Well done !!
Martin
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Old 23-10-2020, 12:04 PM
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Sunfish (Ray)
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Excellent detail and colour.
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Old 23-10-2020, 07:40 PM
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Very nice image Fernando. Plenty of detail and the colour looks good. It's just the background noise which is a little distracting but should be easy to remove with some more bias frames I think. Otherwise you can create a really good star mask and isolate the background from the foreground and apply some individual noise reduction passes on each channel.
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Old 24-10-2020, 03:21 AM
Fernando
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Thank you all, for comments and suggestions. I am always going back to my images, looking for ways to improve it. Yous suggestions are very wellcome!
Regards, Fernando
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Old 24-10-2020, 06:39 AM
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Really excellent colour, love this. Wondering what setting is your dithering setting?
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Old 24-10-2020, 08:45 AM
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[QUOTE

I do have some amp glow with the ZWO071MC Pro. Still not able to avoid it in my light frames and/or fixing it totally during callibration; a final dynamic crop turns the image aestetically better (see attached). In the previous post, I made a mistake and posted the image still not cropped. By the way, I use darks, flats and dark flats and no bias. I will check the calibration frames, thanks.

Regards, Fernando[/QUOTE]

Hi Fernando, I'm surprised by the amp glow. I have the exact same camera and run at -5deg, often 3-5min subs, as you are and have really pushed it in post-processing and have never yet seen any evidence of amp glow after I've calibrated. Haven't really looked for it is the lights but have never noticed any there either. Wonder if something unique to your setup that's in play if not something wrong with calibration frames. Let us know if you find the culprit!
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Old 24-10-2020, 10:52 AM
Fernando
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Quote:
Originally Posted by mswhin63 View Post
Really excellent colour, love this. Wondering what setting is your dithering setting?

Hi Malcon,


In SGPro Autoguide: Medium Dither, every 3 frames.


Regards, Fernando
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Old 24-10-2020, 10:59 AM
Fernando
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Quote:
Originally Posted by Robert_T View Post
[QUOTE

I do have some amp glow with the ZWO071MC Pro. Still not able to avoid it in my light frames and/or fixing it totally during callibration; a final dynamic crop turns the image aestetically better (see attached). In the previous post, I made a mistake and posted the image still not cropped. By the way, I use darks, flats and dark flats and no bias. I will check the calibration frames, thanks.

Regards, Fernando

Hi Robert,


What I am going to do is take advantage of the never ending clouds and rain down here in Brasil to rebuild all my calibration frames. I will see how it goes.


Regards, Fernando


Hi Fernando, I'm surprised by the amp glow. I have the exact same camera and run at -5deg, often 3-5min subs, as you are and have really pushed it in post-processing and have never yet seen any evidence of amp glow after I've calibrated. Haven't really looked for it is the lights but have never noticed any there either. Wonder if something unique to your setup that's in play if not something wrong with calibration frames. Let us know if you find the culprit![/QUOTE]
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Old 24-10-2020, 12:14 PM
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Fernando, something maybe worth trying is to ditch the dark flats and add bias frames (take lots of them). Also if your mount settles well, you can try and adjust the frequency of dithering to every second frame. Imaging runs will be longer but the data should have slightly better SNR after stacking, giving you a little more headroom when stretching.
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