Author Topic: M42  (Read 105 times)

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The Thing

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M42
« on: Feb 18, 2021, 10:22:44 »
I am a bit mystified by the flatness of the Ha on the right of the picture.

137x60s 2h17m Gain120 Offset 4 Temp-5C 10xDark, 10xFlat, 10xDarkFlat Processed in PixInsight using Weighted Batch Pre-Processing v2 (as easy as DSS!) and EZProcessing scripts with a tweak using Curves Transformation.

Image date, time and location:   2021-02-10, 20:22-00:17, Manche, France
Telescope aperture and focal ratio:   Sharpstar 61EDPH F4
Camera and filters used:   ZWO ASI294 MC Pro, Optolong L-eNhance Ha, Hb, OIII filter
Processing applied:   PixInsight (WBPP2, EZ, CT)

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Carole

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Re: M42
« Reply #1 on: Feb 19, 2021, 11:04:32 »
That's come our really well Duncan.

Very nicely processed except I think the brighter part of the nebula is a bit bright and obscuring detail, did you take any shorter subs to combine?

Quote
I am a bit mystified by the flatness of the Ha on the right of the picture.
As regards your comment above, I had a feeling that Ha was a bit lacking on that side of the nebula and did a search and found this one below.  Whilst there is Ha on that side, it's no-where near as bold and detailed as on the left side.

https://www.astrobin.com/340230/?nc=user

Carole

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Re: M42
« Reply #2 on: Feb 19, 2021, 11:16:31 »
Thanks Carole. Noted about the Ha.

I used a PI function called Masked Stretch, probably need to ratchet it up. The well depth of my asi294 and so it's dynamic range means at 60s I can see the trapezium stars on my main pc. I think conversion to jpeg has lessened the range somewhat, 32 to 8 bit🙁
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RobertM

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Re: M42
« Reply #3 on: Feb 19, 2021, 17:05:46 »
Nice one Duncan and very pleasing colours, pretty good stars in all four corners - I presume this is using the reducer ?

Are you autofocusing yet or is this with a Baht ?

JPEGs are always a PITA when it come to dynamic range.

Robert

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Re: M42
« Reply #4 on: Feb 19, 2021, 18:39:50 »
Thanks Robert. I'm using PhotometricColourCalibration in narrowband mode with the passbands entered.

It is using to the flattener which makes it a 5 element apo. The focus is automatic but I think I need to tighten the grub screws and glue them as it's gone sloppy! The autofocus often fails but it's pretty  good anyway. More tweaking.
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Roberto

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Re: M42
« Reply #5 on: Feb 20, 2021, 17:20:47 »
That's a cracking shot Duncan.  I love the nebulosity and framing.

Roberto

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Re: M42
« Reply #6 on: Feb 21, 2021, 13:59:23 »
Thanks Roberto, high praise much appreciated.
We're all guinea pigs in the laboratory of life. Better a fluffy guinea pig than a lab rat!
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