NGC 247 - The Needle's Eye Galaxy [30hrs Repro]

[Dave882]

NGC247 is part of the Sculptor group of galaxies, only 11Mly away but with a very low surface brightness. Nicknamed the 'Needles Eye Galaxy', this intermediate spiral galaxy is viewed almost edge-one and has quite an interesting shape with its distinct 'hole' possibly caused by collision with a dark subhalo and continued restriction on new star formation in this area. (https://ui.adsabs.harvard.edu/abs/2014MNRAS.443.3260W/abstract)

Captured here with around 14hrs of data from my B7 backyard location. It's taken a couple of months to get enough moonless nights, but seeing conditions were generally very poor, and I needed to throw out quite a bit. Some nice dark sky data would really help to bring out the multitude of background fuzzies in particular the fascinating string of galaxies right on the edge of my fov.

EDIT: Managed to come across a bunch of data I'd already acquired on this object earlier in the year! Done a full repro with double the data - bit of a difference ay?!?

Larger higher res version (https://storage.googleapis.com/dso-browser.com/astrophotography/picture-9eb27cbafbd75c11874498ea6d1d5908-original.jpg)

Comments and critique welcome as always :)

Image Detail:
just shy of 30hrs of 60sec subs
C14 non edge @f7 with the Starizona reducer LF
EQ8 pro
Asi2600mc pro gain 100 (no filter)
Asi220mm / celestron OAG
ZWO EAF
ASIAIR pro / APP / PI

Thanks for looking

[TrevorW]

Was going to do this last night but the winds picked up, good effort these galaxies need a lot of data for decent detail to come out :)

[Startrek]

Dave,
This is an excellent image of NGC 247 with plenty of fine detail exposed, especially the tiny Star groups in the outer spirals
It’s quite a faint target but those hours have done the trick for you
Well done !
That big scope has done it again
I’ve only imaged this once a few years ago with my old 8” metal newt and ended up with a smudge and very little detail
Definitely requires some decent aperture , focal length and integration time.

Cheers
Martin

[Dave882]

Thanks Trevor yeah it's so hard to resolve these faint background galaxies with all the city light noise - and to make matters worse they were right on the edge of my fov so lots of stacking noise too. I hope you get the chance to shoot this one later on!

[Dave882]

Cheers Martin - as always I'm left wishing I had another 10 or so hours to help resolve some of the small stuff but yes still quite pleased how it came out. I've just had very bad luck with smoke/cloud/wind the last few months I couldn't believe I only had 14hrs of useable data from 6 nights of shooting!!

[Addos]

well done Dave! Good job processing, you got some nice colour saturation and contrast! I mightve not cut the background black quite as hard, but the galaxy does stand out really nicely the way you've approached it. I like the vibrancy of the blues :) Star shapes look good too!

Great job! Also hats off for getting ~850 subs and going through that process :)

[Dave882]

Thanks for your kind words Adam. I think you’re right I reckon I might repro this with a slight shift in the histogram. And yeah there a lot of data in these projects it’s becoming very hard to wrangle!

[Dave882]

Well well well - guess what I just found on my hard drive when I was packing away all my project data... another almost 16hrs on NGC247 I shot earlier in the year but never processed! I'm not sure whether I should feel stupid or like Christmas came early, maybe both, but anyways I felt that she deserved a full repro and so here's the updated image. :D

Larger higher res version (https://storage.googleapis.com/dso-browser.com/astrophotography/picture-9eb27cbafbd75c11874498ea6d1d5908-original.jpg)

[alpal]

Wow Dave - that's looking better -
you have more of the red colour and detail showing through.

cheers
Allan

[Dave882]

Thanks Allan!. Yeah it was actually so much easier to process with the extra data, the detail just responded so well to decon/noise reduction and yes the Ha regions were almost invisible in the first version. I felt like I maybe pushed the first one too far so it looks a bit more natural too imo. Cheers

[gregbradley]

Very nice image. Only suggestion is there is still a bit of background gradients of blue and red that are just visible that could be processed out.

Greg.

[Dave882]

Cheers Greg. Yep you’re right and I think I did make an attempt to reduce that a bit but certainly could do a bit more- I’ve got an idea now how to tackle that now so will have a play with the data. I really appreciate your input :)

[Addos]

Hey Dave - great revision! more saturation and red's without detracting from the blue, great job!


What I do for RGB backgrounds with nasty gradients is pull the stars (or do it earlier in the process before reblending stars), range mask with plenty of smoothness, apply then desaturate background. If strong greys result, darken contrast with normal curves (with background mask still applied). may need to accept a little residual colouration if the result doesnt blend naturally with the unmasked areas. add back stars and maybe do a final curve / saturation adjust. obvs these are pix processes but I'm sure it could easily be replicated in other software.


short of all of that, graxpert is exceptionally good with background gradients so if you feel like going right back to linear stage and dont want to futs around with masks / curves, this might be a good option.

either way you've landed at a quality image here - well done once again!

[Dave882]

Thanks Adam I really appreciate the input. I’ll have a bit of a play with it in PI. I’ve got star-exterminator too so can mask it up and see how that goes.

[strongmanmike]

That's a great shot Dave and what a surprise bonus with the resurrected data, it's made a difference :thumbsup:

Mike

[Dave882]

Cheers Mike. It was such a surprise, and just after I’d commented that I felt my original effort was about 10hrs short for the target too! Wish I could do that on every project, just snap my fingers and voila!!
I’ve been struggling to maintain all my data of late with some of these projects running at well over 100GB I’m going a bit batty keeping things organised.

[Ryderscope]

Thanks for posting a fine version of this galaxy David. It is definitely an interesting target with its complex morphology :thumbsup:

[matlud]

Excellent work there David, the extra data made a big difference and you have picked up nice detail 😀

[Dave882]

Thanks Rodney, Mathew. Glad you liked it!

[SB]

Very nice Dave!

[Dave882]

Cheers Chris!

[Paul Haese]

The second lot of data has given the image more definition and brightness. Nicely done.

[Dave882]

Thanks Paul!

[joshman]

Fantastic Image Dave! The revision was definitely worth the effort,much better definition and clarity. The colours and contrast have also definitely benefitted from the extra data.

[Peter Ward]

Was this taken from Padstow? (10 minutes up the road from my digs)
Quite remarkable is that is the case.
Well done :thumbsup:

[Dave882]

Thanks Josh I appreciate the comments! Definitely need some serious integration when imaging from the suburbs to get that contrast. Still some gradients/noise that lurks beneath unfortunately!

[Dave882]

Cheers Peter - yep all data taken from Padstow. It's a damn hard slog trying to cut through all the noise in the city - I think 30hrs of moonless data is about where I need to be on these fainter broadband targets to get a decent result but yeah that corresponds to a lot of clear nights! Glad you liked the result!