Eridanus spiral NGC 1232

[alocky]

Catalogued as Arp 41, or NGC1232 and 1232A This is a beautiful magnitude 10.1 SAB(rs)C face on spiral, with a smaller SB(s) 15.2 magnitude spiral companion.
This is a beautiful object visually in the 25", and although I have several records and descriptions in my notes over the years, I had completely forgotten this object until I was browsing the Herschel catalogue.
Details are 16"f3.6 newt on an unguided direct drive mount, 10km from the Perth CBD. Camera was a QSI683 struggling to stay below -20C, and over about 4 nights I was able to get about 40 5 minute subs per filter to produce this.
Hi res version at astrobin here:
https://www.astrobin.com/full/323274/0/
thanks for looking, and opinions and constructive comments welcome!
cheers,
Andrew.

[Peter Ward]

Maaaaaaate. Like a fresh breeze. Nice one :thumbsup:

[alpal]

Hi Andrew,
amazing shot of such a dim target.
I think it needs some more saturation of the galaxy & brighter stars
& less saturation of the background.
I'll have a go & post a result if you want?

cheers
Allan

[alocky]

Cheers Peter!


Sure, knock yourself out. I'm not sure I agree on the saturation though, it's a bit like perfume. If you keep overdoing it you end up being desensitised to it, and keep piling it on until people avoid getting in a lift with you.
The background was pretty noisy, so I'm curious to see how it looks with a bit more fiddling.

[strongmanmike]

Amazing work from your location and that street light you have nearby :scared: mate, and such a fantastic looking galaxy this one, nice job :thumbsup:



He he he...love this analogy Andrew :thumbsup:....so yikes, ya wouldn'ta liked my strong perfume version taken with the AG12 four years ago then :lol:
Mike

[RickS]

A nice result, Andrew!

[billdan]

Well done Andrew, very pretty.

[alpal]

Hi Andrew,
OK - just a quick, 5 minute go with LAB mode increased saturation on all the bright stuff
& a reduction in saturation on the dark areas -
using blurred layer masks.
Is this better?
https://www.astrobin.com/full/323510/0/?nc=user

cheers
Allan

[alpal]

OK - this time I did a longer reprocess - about 30 minutes.
I split into RGB channels & worked on the background levels to
get rid of the dark black areas.
I recombined & did the same LAB mode boost for bright areas etc.
I did some sharpening of the galaxy alone using blurred layer masks.
I put a doughnut ring around the galaxy to boost
the low light levels at the edges.
I think this looks better?

https://www.astrobin.com/full/323526/0/

cheers
Allan

[DJT]

Hi Andrew
Great image, detail is really good.
Looking around tinterweb, it doesn’t need much. You have a lot of good data there. Only thing I could suggest is to get that RGB histogram aligned a touch.
Tricky bugger so well done given constraints.

What’s your processing poison of choice?

[alocky]

Cheers Allan - OK I'll pay that. Nice job without overdoing it. And it gives me an idea of what to chase after with the full data too.

[alocky]

Hi Andrew
Great image, detail is really good.
Looking around tinterweb, it doesn’t need much. You have a lot of good data there. Only thing I could suggest is to get that RGB histogram aligned a touch.
Tricky bugger so well done given constraints.

What’s your processing poison of choice?

Thanks Dave,
Processing workflow at my end was all pixinsight. After weeding out the worst of the haze and cloud affected subs, it was standard batch preprocessing (bias darks flats), local normalisation then drizzle integration. In the linear world I gave the Lum a smidge of decon using a lum mask to limit where it worked. I balanced the RGB using the photometric calibration tool. This is why the galaxy is white, because that was the setting I used. I might re-do it using G2V stars as a reference instead. Then a touch of denoise using the multiscale wavelet tool before transforming eveything into non-linear.
Then I didn't do much except hit the saturation a little, play with the curves to try and boost contrast a bit, then TGV denoise and unsharp mask. I'll revisit the non-linear workflow, but had already spent too much time staring at it and it was a nice weekend and the kid were already in the pool...

[alpal]

Thanks Andrew,
PI sounds good but I think most images need a tweak in Photoshop to add the final touches.
It's great data & all the colours are there in your data as per other
images I found on Google -
right up the nice yellow core.

cheers
Allan

[Retrograde]

Very delicate. Super job!

[Regulus]

Nice result Andrew.
it's a good looking spiral, and it looks good in Hi-Res.

Trev

[RickS]

Hi Allan,

It takes a little while to figure out how to do colour manipulation in PI, but it is entirely possible and IMO the tools are every bit as powerful as PS.

Cheers,
Rick.

[alpal]

Hi Rick,
PI has many functions specifically designed for astro images.
PS cannot compare to that however I think most top imagers use both.
I've never used PI but I know how powerful it is.

cheers
Allan