Orpington Astronomical Society

Astronomy => Astrophotography => Topic started by: The Thing on Apr 14, 2020, 15:50:20

Title: Caldwell 32, NGC4631, The Whale.
Post by: The Thing on Apr 14, 2020, 15:50:20
I've always fancied having a go at this galaxy since it always looks good in other peoples images. This is only 18 x 300s subs (+15 Darks, 10 Flats, 10 Dark Flats) at unity gain taken through my Meade LX 90 8" UHTC SCT circa 2006 which is not the worlds best scope so please excuse the star shapes. No reducer flattener was used so its F10 which gives a tiny 0.39 degree wide FoV.

I stacked the subs in ASTAP which most people use for plate solving. Its very good at that. But it also is very good at stacking. DSS would not stack these as the it doesn't recognise the stars as star and PixInsight just laughed. ASTAP has no problem once I had learnt what options to choose. Its very fast and quite smart, it even has a special debayer routine that put colour in the stars! I'm impressed. Post-processing was attempted in PixInsight with DarkTable used to do final sharpening and noise reduction. It looks far better at small scale! I hope to get a few more hours on this tonight 14/04/20.

(http://gallery.orpington-astronomy.org.uk/albums/userpics/10050/normal_LIGHT_E300__clone_IV_DT.jpg) (http://gallery.orpington-astronomy.org.uk/albums/userpics/10050/LIGHT_E300__clone_IV_DT.jpg)

Image date, time and location:   2020-04-11, Manche, France
Telescope aperture and focal ratio:   Meade LX90 UHTC 8" F10
Camera and filters used:   ZWO ASI294MC Pro, IDAS LPS-D1 LP filter
Processing applied:   ASTAP, PixInsight, DarkTable
Title: Re: Caldwell 32, NGC4631, The Whale.
Post by: MarkS on Apr 14, 2020, 20:18:21
A good result Duncan!   It's another one I've never tried.

More subs will definitely help this.

Mark
Title: Re: Caldwell 32, NGC4631, The Whale.
Post by: Roberto on Apr 15, 2020, 14:28:48
Excellent close-up!  There's so much going on in this galaxy!

Roberto
Title: Re: Caldwell 32, NGC4631, The Whale.
Post by: NoelC on Apr 16, 2020, 11:22:51
What a tiny little target!
Well done Duncan, nicely processed too.
Noel
Title: Re: Caldwell 32, NGC4631, The Whale.
Post by: The Thing on Apr 16, 2020, 13:31:50
Thanks guys. For only 90 minutes data at f10 its come out very nicely. I have another 25 x 300s or 2h5m of data to add from the night before last (14-15/4) so hopefully it will get better.
Title: Re: Caldwell 32, NGC4631, The Whale.
Post by: RobertM on Apr 16, 2020, 19:32:24
Nice one Duncan ! It's quite a short integration time so more subs should improve it quite a lot.

Robert
Title: Re: Caldwell 32, NGC4631, The Whale.
Post by: The Thing on Apr 17, 2020, 13:19:14
58 x 300s subs, nearly 3 hours 5 hours!, stacked in ASTAP which also does the initial debayering and colour correction using its own algorithm if you let it, in 157 seconds the lot!  Then ABE, PCC, CS, DPSF, DECON, HT in PixInsight for those that know the acronyms.

(http://gallery.orpington-astronomy.org.uk/albums/userpics/10050/normal_WHALEGALAXYNCG46_2020_04_15_58x300L_LX90_8_UHTC_ZWO_ASI294MC_Pro__stacked_ABE.jpg) (http://gallery.orpington-astronomy.org.uk/albums/userpics/10050/WHALEGALAXYNCG46_2020_04_15_58x300L_LX90_8_UHTC_ZWO_ASI294MC_Pro__stacked_ABE.jpg)
Title: Re: Caldwell 32, NGC4631, The Whale.
Post by: RobertM on Apr 17, 2020, 14:03:52
:)

Looking really greeeaat !

How about going for 6 hours next ?

Robert
Title: Re: Caldwell 32, NGC4631, The Whale.
Post by: Carole on Apr 17, 2020, 16:24:41
The 2nd version with the extra data is looking really good, the first one was a bit clipped I thought, but this one has come out really well.

Carole
Title: Re: Caldwell 32, NGC4631, The Whale.
Post by: The Thing on Apr 17, 2020, 16:28:27
Thanks Robert and Carole. More clear as sky in a couple of days...
Title: Re: Caldwell 32, NGC4631, The Whale.
Post by: NoelC on Apr 17, 2020, 18:34:59
Very good.
Noel
Title: Re: Caldwell 32, NGC4631, The Whale.
Post by: ApophisAstros on Apr 19, 2020, 18:57:40
Agree that the second one is worth the extra data,like it.
Roger