Author Topic: North America Nebula Region  (Read 366 times)

Offline Astrodoc

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North America Nebula Region
« on: 2019 July 29 17:24:38 »
I continue to be impressed by both the Optolong L-eNhance filter and the QHY367C one-shot colour camera for this type of target.
http://astrodoc.ca/ngc7000-2019/

Clear skies,
Ron Brecher
Clear skies,
Ron

Offline mmnb

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Re: North America Nebula Region
« Reply #1 on: 2019 July 29 21:51:31 »
Very nice!
Do you mind elaborating on reasoning behind to the two background reduction steps? I always only do 'subtract', now I've only just  heard of  Carlos' method (which I can't actually find now) where he does some sort of linearization of the bg model and then only subtraction.

Offline Astrodoc

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Re: North America Nebula Region
« Reply #2 on: 2019 August 12 18:08:36 »
Division to remove multiplicative gradient (imperfect correction of flats, for example). Subtraction to remove additive gradients. I don't always use both; it depends on the image. Subtraction on its own can give a very nice result most of the time.

Clear skies,
Ron
Clear skies,
Ron