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)
(http://gallery.orpington-astronomy.org.uk/albums/userpics/10050/normal_M42_137x60s_2h17m_G120_O4_T-4_D_F_DF_PI_EZ.jpg) (http://gallery.orpington-astronomy.org.uk/albums/userpics/10050/M42_137x60s_2h17m_G120_O4_T-4_D_F_DF_PI_EZ.jpg)
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?
QuoteI 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
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🙁
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
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.
That's a cracking shot Duncan. I love the nebulosity and framing.
Roberto
Thanks Roberto, high praise much appreciated.