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OSC processing


(@jmadhavan)
Hydrogen Atom Customer
Joined: 2 years ago
Posts: 1
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Is there a tutorial for OSC processing in APP?  All I can find is OSC along with Narrow band etc. but none for simple OSC integration and processing.

 

Thank you

 

Jas


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(@vincent-mod)
Quasar Admin
Joined: 5 years ago
Posts: 4727
 

Most steps for OSC are the same as in the combined tutorial. You can basically leave all settings to default for regular OSC processing. Things you may want to switch on are LNC and MBB in tab 6, also just use their defaults.

Basically you load in your OSC data as lights, add the calibration data and go to tab 6 and click integrate. That should give you a nice result already.


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(@applal)
Brown Dwarf Customer
Joined: 1 year ago
Posts: 11
 

When I try to create master flats, I get really bizarre results with OSC. Would I be better off just adding in the sub flat frames to the lights I am processing and let APP create the master flat that way? There is very little guidance as to processing OSC.


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(@wvreeven)
Galaxy Admin
Joined: 4 years ago
Posts: 1645
 

@applal Hi Alan, yes it always is best to let APP create the masters.


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(@applal)
Brown Dwarf Customer
Joined: 1 year ago
Posts: 11
 

@wvreeven Thank you, but, and not to be argumentative, only curious, why can't the APP just create Master Flats from flat subs without Lights data? This was troubling even when I was shooting RGB. I always was reverting to Nebulosity to make my calibration frames to then use in APP. 


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(@wvreeven)
Galaxy Admin
Joined: 4 years ago
Posts: 1645
 

@applal What version of APP are you using? APP has been able to create master flats without lights for many versions now. Just load the raw flat frames and either raw dark flat frames or a master dark flat created by APP, go to tab 2 and click "create Masters & assign to Lights". Note that, as always, if the exposure time of the dark flats is not the same as the lights, you'll need either raw bias frames or a master bias. The text on the button may seem to suggest that Lights are needed but this is not the case.


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(@applal)
Brown Dwarf Customer
Joined: 1 year ago
Posts: 11
 

1.083.2 (1.083.2) - 

I just attempted exactly what you described. Just with flat calibration files.

It came out as green, with 3 different intensities, as distinct "panels"  from top to bottom.  

I had NO other files, just the flat frames. And looked at individually, they looked like one would expect. I would like to know, on the very first panel that opens when adding the Flats to the Flat button, it asks "To Which Filter..... assign..." Do I select RGB, All Channels? do I deselect everything? There is no hint to guide one to the knowing in the case of just making masters. 

When I go to do as you described, "Create masters and assign to lights" I get the Critical warning error, and just ignore it.

I just ran it with All Channels, and this is the result. My concern is not so much the green, as much as the sharp horizontal line near the middle. I have attached a screen shot for you to see. And could you comment on the question of what to select, and should the Master Flat be green?

Screen Shot 2022 04 15 at 10.40.24 AM

 


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(@wvreeven)
Galaxy Admin
Joined: 4 years ago
Posts: 1645
 

@applal As I wrote in my previous comment, dark flats are required in APP to create a proper master flat. Since you wrote that you only processed flats, the result isn't what it is supposed to be and you get the critical warning popup. Please try again with dark flats and verify that that solves your issue.

Regarding the question what channel to apply, APP should offer to apply the "FILTER" tag at the bottom of the popup and that is enough for your flats since APP detects that they are RGB images. As soon as your flats have loaded in APP you can verify that by looking at the entries in the file list at the bottom of the APP window. There APP will indicate that it has loaded the flats as RGB flats:

Screenshot 2022 04 15 at 12.11.18

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(@andybooth)
White Dwarf Customer
Joined: 4 months ago
Posts: 18
 

Alan, just to give confidence,

i also have osc asi071mc.

do a flat dark, same exposure, gain, temp as flat.

Also note: in default viewer, if you do not click neutralise background when looking at a raw file from a rggb colour chip, you will see a green file, as two green pixels to each of one blue and red.

I am sure you know this, and you are just commenting on the band, but just for info.

Personally, i have a master flat i create with just the flat and flatdark files and use it until i change anything in the imaging train. No need for the lights in creating.

works out of the box for me.

This post was modified 1 month ago 2 times by Andy Booth

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(@applal)
Brown Dwarf Customer
Joined: 1 year ago
Posts: 11
 

Thanks to both Andy, and Wouter-Moderator for your simple to understand guidance.

While it was not as intuitive as I expected, it is fine and certainly works! And I also found what caused that strange horizontal line in the image I uploaded to this thread. It turned out, that, for reasons unknown, I had a few flats subframes that were only half illuminated. Once I deleted them from the processing, THAT problem was gone. APP and I are once again getting along just fine. 


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