Antares / Rho Ophiuci

AstroViking (Steve) · #1 30-05-2023, 09:00 PM

Hi all,

I thought I'd just throw this one out for comment. It's not the first time I've imaged this target, so I sort-of know what I'm aiming to get at the end.

I'm not really happy with the final result, as the nebula regions don't seem to be separate from the stars in the background.

I know a lot of people go for over-saturated colours and turn it into a neon playground, and that's really not my taste.

One good thing to come out of the night's work was the astounding feat of polar aligning the Star Adventurer. I guesstimated which way was south, gave the altitude adjuster a nudge, and when it was dark enough to PA through the polar scope, Octans was IN MY FOV! I have never had that happen before, and especially not when I pointed the thing in a random direction... For those of you with an SA, you'll know how difficult it is to PA these things through their polar scope.

Taken at Lake Tyrell with my DSLR and 90mm lens. A stack of 100 * 20 second exposures at ISO 3200, f3.2. Processed with SiriL and Affinity photo.

Cheers,
V

raymo · #2 30-05-2023, 09:49 PM

just how I like it. I dislike the technicolour images we are seeing nowadays.
raymo

xelasnave · #3 31-05-2023, 07:24 AM

That is a great image Steve well done.
I dont like the colour of so many images ...particularly mine.
Alex

RB (Andrew) · #4 31-05-2023, 07:46 AM

Nice one Steve.

AstroViking (Steve) · #5 31-05-2023, 08:49 AM

Raymo, Alex and RB, thanks very much for the compliments!

Dave882 (David) · #6 31-05-2023, 09:32 AM

Yeah that’s lovely mate well done!!

JA · #7 31-05-2023, 10:23 AM

Quote:

Originally Posted by AstroViking

Hi all,

I thought I'd just throw this one out for comment. It's not the first time I've imaged this target, so I sort-of know what I'm aiming to get at the end.

I'm not really happy with the final result, as the nebula regions don't seem to be separate from the stars in the background.

Hi V,

Firstly, lovely image of a beautiful object. If you want more separation between the nebula and background you need to increase the signal to noise ratio of the image, and from what I can see you would benefit greatly, especially in such a dark location, with dropping the ISO from 3200 to something in the 400-800 iso range, shooting RAW if not already doing so and increasing exposure duration to achieve that and the attached image shows why.....

I note from another thread that your DSLR may be a Nikon D7100 so the attachment reflects that.

Best
JA

Attached: Nikon D7100 RAW ISO Series ISO100 to ISO12800 prepared from DP-Review data

NOTE: The screenshotting as well as the JPG compression resulting from IIS compression on upload has smoothed the image somewhat for the higher ISO shots. Go to DP Review website to view the more accurate (noisier) images at higher ISO.

Rory · #8 31-05-2023, 11:29 AM

Hi Mate, Great image - especially for such a short integration time.
Do you separate your image into a stars and starless layer for editing?

Stephane · #9 31-05-2023, 12:58 PM

Very nice Steve. A beautiful region of the sky.

AstroViking (Steve) · #10 31-05-2023, 01:46 PM

Hi all,

Thanks for the praise JA, Rory, Stephane and David. Much appreciated!

To answer the questions (in no particular order):

JA - It is a D7100 camera and thanks for the suggested ISO change. I'm hoping to get to a dark(er) sky site in the near future, so can always try again with a lower ISO and see what eventuates. (Thinking about it, I can see how dimmer stars would give a better separation between nebula and background.)

Rory - No, I didn't process this one by separating it into star / starless layers. I did have a go with starnet++ in SiriL last night but the end result was.... not good. It is something I want to get better at and hopefully integrate into my workflow.

Cheers,
V

Rory · #11 31-05-2023, 02:44 PM

Nice - For me separating the stars and starless is crucial to emphasising the nebula without the stars getting out of control.

I use Pix Insight and StarXterminator,

but if you use Starnet,
in photoshop -take the starless image as a layer and subtract it from your original. Then you'll have a stars and starless layer.
Then blend the stars with the blend function 'screen' you can easily adjust the size and intensity with a clipped levels adjustment layer.
You can then boost the crap out of your starless to make it pop with curves and hue saturation etc.

Pretty sure you'd be able to do all this in GIMP but I've never used it.

If you want to upload your stacked raw file I'd love to have a play with it haha.

Cheers!

oska (John) · #12 31-05-2023, 04:56 PM

Lovely V, and with some text all is safe again in the (my) world.
But how do you know you don't like the more saturated images, you've never tried :p

carlstronomy (Carl) · #13 31-05-2023, 05:16 PM

Another nice image Steve. Love the widescreen versions, sit and eat some popcorn!

I agree natural colours all the way!

AstroViking (Steve) · #14 01-06-2023, 08:56 AM

Thanks again for all the compliments, folks. Makes me feel a lot better that my images aren't all crap...

Rory - I'll give the star / starless layers a go (maybe tonight) and see what eventuates.

Oska - I've seen the hyper-saturated images and think they're awful. As soon as mine started heading in that direction it was a quick U-turn back to normality.

Cheers,
V

Bodon (Steve) · #15 01-06-2023, 10:29 AM

Really nice pic there!