This is my first effort with my RASA and the ASI 071.
Lights 100x$0s
Darks 100
Flats/DFlats 20
Bortle 3 (rural France)
Gain 95
Temp -5
APT
Ivo, I would be grateful if you could assess the data and processing (feel free to have a go yourself )
Anyone else want to play, feel free.
https://www.dropbox.com/sh/xz8y3wmw454s ... KuWLa?dl=0
https://www.astrobin.com/9hs564/
Messier 4 Rasa 8" ZWO ASI071 MC Pro
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- Posts: 65
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Messier 4 Rasa 8" ZWO ASI071 MC Pro
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- M4.jpg (416.59 KiB) Viewed 6539 times
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- Posts: 65
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Re: Messier 4 Rasa 8" ZWO ASI071 MC Pro
Tried again.
This time I used the 'Sample' method for colour.
Which do people think is better or prefer?
David
This time I used the 'Sample' method for colour.
Which do people think is better or prefer?
David
Re: Messier 4 Rasa 8" ZWO ASI071 MC Pro
Sample image for me , very nice image indeed loads of colour, I will have a play with your data when I get a minute .
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Re: Messier 4 Rasa 8" ZWO ASI071 MC Pro
Burly
Thanks, I lean that way too. If you have a play if you post it I would be grateful if you could include a copy of thelog. It all helps with the learning process
Cheers
David
Thanks, I lean that way too. If you have a play if you post it I would be grateful if you could include a copy of thelog. It all helps with the learning process
Cheers
David
Re: Messier 4 Rasa 8" ZWO ASI071 MC Pro
For accuracy, I'd say your initial image is more accurate.
M4 is old, meaning it has an overabundance of older stars yellow/red stars (indeed, it is home to many white dwarfs), given that any bright blue giants would have long expired. So, a yellower appearance of the cluster is to be expected.
As is the case with many OSCs., your ASI-071 shows an increased green response in the higher wavelength, which tends to make things more yellow. This is hard/impossible to balance out. The solution is to use a luminance filter (aka IR/UV filter) that cuts this response before it increases again.
I can't quite tell whether you used such a filter here, as the yellowing does not appear to be too bad compared to some other instruments having the same quirk/feature. However, the foreground (random) star field should exhibit a good random distribution of star colors, but is IMHO comparatively lacking in blue stars a little with an over-abundance of orange stars, providing some anecdotal (not conclusive) evidence that there a slight yellow bias. At the end of the day, just increasing the blue bias from the default color balance goes a long way I think, arriving at something in between the two images you posted.
Hope this helps at all!
M4 is old, meaning it has an overabundance of older stars yellow/red stars (indeed, it is home to many white dwarfs), given that any bright blue giants would have long expired. So, a yellower appearance of the cluster is to be expected.
As is the case with many OSCs., your ASI-071 shows an increased green response in the higher wavelength, which tends to make things more yellow. This is hard/impossible to balance out. The solution is to use a luminance filter (aka IR/UV filter) that cuts this response before it increases again.
I can't quite tell whether you used such a filter here, as the yellowing does not appear to be too bad compared to some other instruments having the same quirk/feature. However, the foreground (random) star field should exhibit a good random distribution of star colors, but is IMHO comparatively lacking in blue stars a little with an over-abundance of orange stars, providing some anecdotal (not conclusive) evidence that there a slight yellow bias. At the end of the day, just increasing the blue bias from the default color balance goes a long way I think, arriving at something in between the two images you posted.
Hope this helps at all!
Ivo Jager
StarTools creator and astronomy enthusiast
StarTools creator and astronomy enthusiast
Re: Messier 4 Rasa 8" ZWO ASI071 MC Pro
Do you have the original fits file not the tiff
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- Posts: 65
- Joined: Tue Oct 22, 2019 5:58 pm
Re: Messier 4 Rasa 8" ZWO ASI071 MC Pro
BurlyBurly wrote:Do you have the original fits file not the tiff
I just noticed this....or I don't remember responding
the autosave fit is in dropbox
David