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Workflow suggestions for integrating galaxy OSC subs and monochrome L and Ha subs

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(@wvreeven)
Galaxy Admin
Joined: 4 years ago
Posts: 1649
 

@skogpingvin I think I didn't make myself clear. I meant for you to upload NGC1365-RGB-session_2.fits. Can you do that please?


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(@skogpingvin)
Brown Dwarf Customer
Joined: 3 years ago
Posts: 13
 

@wvreeven OK, sorry! It's there.


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(@wvreeven)
Galaxy Admin
Joined: 4 years ago
Posts: 1649
 

@skogpingvin Thanks! It looks like something went wrong while integrating the subs because this image essentially is a B/W image and doesn't contain any color. As soon as step 6 is done, the integration result is displayed in APP. In the upper right you can find the histogram of the image. In case of an RGB image the histogram is supposed to show colors but that is not the case:

Screenshot 2021 11 10 at 09.41.43

Can you upload a raw light as well so I can see what that looks like?


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(@skogpingvin)
Brown Dwarf Customer
Joined: 3 years ago
Posts: 13
 

@wvreeven

Posted by: @wvreeven

Can you upload a raw light as well so I can see what that looks like?

I can't get onto the upload site at the moment, but the sub is definitely a colour image - it's a horrible yellowy green colour!

image
This post was modified 7 months ago by skogpingvin

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(@wvreeven)
Galaxy Admin
Joined: 4 years ago
Posts: 1649
 

@skogpingvin There was some maintenance at the server today. It is working now. Can you try again please?


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(@skogpingvin)
Brown Dwarf Customer
Joined: 3 years ago
Posts: 13
 

@wvreeven OK, uploaded now. There's always a satellite!


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(@wvreeven)
Galaxy Admin
Joined: 4 years ago
Posts: 1649
 

@skogpingvin There is no Bayer information in the FITS header of your raw files. So in tab 0 you need to set the pattern to RGGB and tick "force Bayer/X-Trans CFA". However, when you do that and also load the L and Ha files, then those will be debayered as well and they shouldn't.

So your workflow will be

  • Start APP
  • Go to tab 0, set the pattern and check "force Bayer/X-Trans CFA"
  • Go to tab 1 and load the RGB lights and calibration files.
  • Go to tab 6 and click integrate
  • Go back to tab 0 and uncheck "force Bayer/X-Trans CFA"
  • Go to tab 1, unload all files and load the L and Ha lights and calibration files
  • Go to tab 6 and click integrate
  • Go back to tab 1, unload all files and load the RGB, L and Ha integration result
  • Go to tab 4 and click "start registration". When done, click "save registered frames"
  • Go back to tab 1, unload all files and load the registered frames
  • Go to tab 2 and click "create Masters & assign to Lights". When done check "split channels" and click "SAVE (calibrated) Light frames.

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(@skogpingvin)
Brown Dwarf Customer
Joined: 3 years ago
Posts: 13
 

@wvreeven Sorry about the delay, I was on a work trip (servicing astronomical domes - I love my job!)

I haven't gone through your last message, but just to re-cap, the five files I have are:

  • NGC1365-RGB-session_2-RGB-session_2-cal-Red.fits
  • NGC1365-RGB-session_2-RGB-session_2-cal-Green.fits
  • NGC1365-RGB-session_2-RGB-session_2-cal-Blue.fits
  • NGC1365-Hydrogen-alpha-session_1.fits
  • NGC1365-Luminance-session_1.fits

The first three files are 32b grey, but the last two (Ha and L) are marked as 32b RGB, which seems wrong. This makes the combine RGB tool ask me for lots of extra information about which channel of each file is shot using which filter. Clearly the Ha and L files should be 32b grey.

I assume the workflow you have provided will short this out.

I'll have a go at this soon, but work beckons again. I just wanted to let you know I haven't forgotten you, and I'm very grateful for the help!


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(@wvreeven)
Galaxy Admin
Joined: 4 years ago
Posts: 1649
 

@skogpingvin The Ha and L files should be mono as well and not RGB. This is because "force Bayer/X-Trans CFA" was enabled. If you follow my new recipe then they will come out as mono files.


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(@skogpingvin)
Brown Dwarf Customer
Joined: 3 years ago
Posts: 13
 

@wvreeven I've done that, and got a result! This is the text I've written for my local Astronomical Society.

 
It was a challenge - I made things hard for myself by using two scopes and two cameras. The colour information was 51x5 minute exposures using an ASI071MC-P on a Sidereal Trading modified saxon 102mm FCD100 triplet with the Astroworx focuser made in our factory. The monochrome information was 20x5 minute exposures in Ha and 27x5 minute exposures in Luminance using my SharpStar 107mm FPL53 triplet and an ASI1600MM-P.
 
An additional challenge was the idiot I had to work with: me. I neglected to re-calibrate PHD on the colour camera after rotating the guide camera, so the first exposure drove the mount wild, and I didn't re-centre after I finally did re-calibrate. This resulted in terrible framing. I wanted some of the Fornax cluster but only got a couple.
 
Processing these into five stacks was difficult but once I got the workflow right (thanks to super-helpful Wouter at APP) it was pretty straightforward.
I like the addition of Ha into the red channel. It emphasises the little knotty nebulas in the arms of the galaxy. I left the image pretty noisy as I didn't want to erase little galaxies in the background - and there are lots.
 
Overall, working with two scopes simultaneously is difficult. Not only the processing, but the data gathering is a real juggling act, and I made lots of mistakes. Part of the enjoyment of astrophotography is the quiet, almost meditative atmosphere at the scope while it does its thing. Instead of this, I was running around like a chook without a head.
 
I give myself three stars. Please don't reduce my score with Starnet++!

 

NGC1365 LHaRGB PS

 

This post was modified 6 months ago by skogpingvin

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