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M3 core region at 1" resolution

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#1 Jan_Fremerey

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Posted 15 May 2020 - 05:20 AM

DSO_233823_lapl4_ap45_P75_lumi_itGr154x4_11K9-65K5_g201_mit RGB_01_15-255_800sq.jpg

 

Taken last night with 10" f/5 prime focus camera ZWO ASI178MM. L: 75% from 2,000x500ms - RGB: 75% from 500x1s each.

 

CS, Jan

 

 


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#2 happylimpet

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Posted 15 May 2020 - 06:39 AM

Autostakkert, some sharpening? WHat did you use? Looks like when I use iterative gaussian sharpening in FITSWORK.

 

Amazing image! Have you measured the FWHM then?



#3 Jan_Fremerey

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Posted 15 May 2020 - 07:14 AM

Autostakkert, some sharpening? WHat did you use? Looks like when I use iterative gaussian sharpening in FITSWORK.

Have you measured the FWHM then?

Thanks a lot for kind reply! As you say: AutoStakkert!3 without sharpening, but iterative gaussian in Fitswork at radius 1.54, x4, s150, further data documented in file name. FWHM less than 3 px, i.e. 7.2 µm / 1.27 m = 1.2 arcsec



#4 happylimpet

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Posted 15 May 2020 - 07:24 AM

Thanks a lot for kind reply! As you say: AutoStakkert!3 without sharpening, but iterative gaussian in Fitswork at radius 1.54, x4, s150, further data documented in file name. FWHM less than 3 px, i.e. 7.2 µm / 1.27 m = 1.2 arcsec

Funny that I recognised the process from the residuals! I use FITSWORK iterative gaussian a lot - it works very well, though it does leave those distinctive haloes around stars.

 

Your filenames also look like mine!

 

Thats a very impressive result - well done.



#5 Jan_Fremerey

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Posted 15 May 2020 - 08:57 AM

I use FITSWORK iterative gaussian a lot - it works very well, though it does leave those distinctive haloes around stars.

I didn't know where the haloes come from. Do you recommend another sharpening tool? In fact, I don't regard those haloes worse than spikes which astonishingly do not appear in spite of the massive camera holder (http://www.astro-vr.de/100901_3694.jpg), even on much brighter stars.



#6 sunnyday

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Posted 15 May 2020 - 09:00 AM

very pretty, it gives the impression that you go inside.
thank you .



#7 Quaternion

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Posted 15 May 2020 - 09:01 AM

Awesome.  May I ask what Gain you use relative to the max gain setting?  I made the awful mistake of trying 3sec “unlucky” DSO imaging at F5.4 with Unity Gain on an ASI1600 instead of closer to max analog gain, and basically got NO data on M81

except the central core, even with 80min...



#8 happylimpet

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Posted 15 May 2020 - 10:25 AM

I didn't know where the haloes come from. Do you recommend another sharpening tool? In fact, I don't regard those haloes worse than spikes which astonishingly do not appear in spite of the massive camera holder (http://www.astro-vr.de/100901_3694.jpg), even on much brighter stars.

No recommendations. The haloes arent a big deal - and the results are superb.

 

Is that the telescope used? Amazingly minimalist! Wow! You must be in a very dark location.



#9 Jan_Fremerey

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Posted 15 May 2020 - 11:54 AM

Is that the telescope used? Amazingly minimalist! Wow! You must be in a very dark location.

I'm working on our roof terrace under suburban skies, no problem with the open telescope as long as stray light doesn't directly enter the camera tube, i.e. from the terrace floor.
 


Edited by Jan_Fremerey, 15 May 2020 - 03:47 PM.


#10 Jan_Fremerey

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Posted 15 May 2020 - 03:35 PM

it gives the impression that you go inside.

You are right: it's like just passing through the foreground stars ...


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#11 Jan_Fremerey

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Posted 15 May 2020 - 03:41 PM

May I ask what Gain you use relative to the max gain setting?

Thanks for kind reply, I was at maximum gain setting on all channels.




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