The Wizard and a couple of stars

[Stefan B]

While I am still struggling with processing the Helping Hand I was able to gather some data on the Wizard. I got some duoband and broadband data and mixed it via NBAccent as usual. Processing was straight forward and probably didn't even take an hour.

Broadband and duoband was mixed before going through all the modules like contrast, HDR, etc.

This is the result of almost 10 hrs of data:

I don't think that much more time would add much more value. I am quite happy with the outcome so I call it a day.

The field is full of stars. With Ron's Veil image it was already noted that it's probably not very trendy to have them in the final image. And I basically get that. On the other hand I like images with lots of stars. At the same time it's hard to highlight the nebula with so many stars. So I reduced the stars quite a bit but didn't push them back more. I hoped I managed to maintain a natural appearance while getting the nebula in the foreground.

See https://www.astrobin.com/bc34ar/ for details.

Regards
Stefan

[fmeireso]

Well, it is still a nice image despite all the stars. Maybe there are still too many but they sure do show marvelous colors!

[decay]

You are producing images faster than I'm able to write comments on them

One more excellent shot! But I don't see 'a couple of stars'? What do you mean This ocean full of marbles glowing in all colours ... ?

BTW: The quality of your data is _much_ better then mine, in terms of optical (?) aspects. The stars do look much sharper for example, as I saw while processing your very dark dark nebula data set.

Dietmar.

[Stefan B]

Well, it is still a nice image despite all the stars. Maybe there are still too many but they sure do show marvelous colors!

Thanks, Freddy! Despite the sheer number of stars I still like the star field since the stars have various colors and especially various sizes. Stars don't look too uniform although I reduced them heavily.

You are producing images faster than I'm able to write comments on them

That's why I love August/September. The most clear nights compared to other months. Moreover, nights are already pretty long and still warm. After setting up and starting the imaging session it's a pleasure to stay out, watch the stars and maybe have a beer.

BTW: The quality of your data is _much_ better then mine, in terms of optical (?) aspects. The stars do look much sharper for example, as I saw while processing your very dark dark nebula data set.

Mmhh...our scopes are pretty similar. Same f ratio, same manufacturer, slightly different focal lengths. I use a aperture mask which helps a lot in terms of star morphology. In the meantime my mirror is incredibly dirty and requires some cleaning. The last time was certainly more than a year ago. Don't know about yours What somehow appeared to help with sharpness of star spikes was upgrading to the cooled astrocam. Not really sure why.

One more excellent shot! But I don't see 'a couple of stars'? What do you mean This ocean full of marbles glowing in all colours ... ?

Much appreciated. I admit that I am pretty happy with star field and the image overall. It was basically just a test run in order to look if I should more data. But I think I wouldn't gain anything of significance.

Regards
Stefan

[Carles]

Nice image Stefan!!

You could try processing halpha or the whole narrowband fiile in compose as Mono, then on Layer mode, use this as base, open this processed color one, and select color from foreground. Since the narrowband image has less stars by default you might get the best of both worlds. Plus some more detail from narrowband one

Carles

[Stefan B]

Hi Carles,

I already tried that on one or two former images of mine but never have been satisfied. I guess the culprit was that as you said you have less stars in the NB image. But when you layer the color of the NBAccent image over the NB image you get star color where no star detail is. Looking at the layered image you sense that something's off but cannot immediately put your finger on it. Until you see that the image has a strange kind of color mottle.

A similar problem arises when you use the NB image as luminance layer and broadband for RGB. It's a problem if chrominance doesn't match luminance.

But it may be worth another try. Maybe my processing skills improved

Regards
Stefan

[Carles]

Hi Carles,

I already tried that on one or two former images of mine but never have been satisfied. I guess the culprit was that as you said you have less stars in the NB image. But when you layer the color of the NBAccent image over the NB image you get star color where no star detail is. Looking at the layered image you sense that something's off but cannot immediately put your finger on it. Until you see that the image has a strange kind of color mottle.

A similar problem arises when you use the NB image as luminance layer and broadband for RGB. It's a problem if chrominance doesn't match luminance.

But it may be worth another try. Maybe my processing skills improved

Regards
Stefan

Hi Stefan,

yeah, but I mean the fact you have less stars in Halpha, for instance, is that it will color only the stars available, resulting in RGB stars, but less, and more contrast.

I've done a test with my HaRGB Bubble Nebula , although wasn't able to do a processing result I'm happy with, yet.. but is OK to illustrate this.
This is with Compose, HaRGB using NB Accent too.

2024-09-09 at 17.33.54.jpeg (401.45 KiB) Viewed 5462 times

Then I used Compose to isolate Halpha (opening on Luminance and Red), did some light processing and after, in Layer module, added the color from the previous one. Resulting in less and dimer stars, without using Shrink module.

2024-09-09 at 17.56.26.jpeg (348.7 KiB) Viewed 5462 times

More work would yield better result, but anyway, I think is a technique that helps with populated starfields when there's nebula present.
cs

Carles.

[Stefan B]

Hi Carles,

thanks for the comparison! Looks promising.

yeah, but I mean the fact you have less stars in Halpha, for instance, is that it will color only the stars available, resulting in RGB stars, but less, and more contrast.

My reasoning is different. Assume there's a part of the nebula where you have a star in the NBAccent image but no star in the NB image. In the NB image you have only nebula. If you layer the color of the NBAccent image onto the NB image you will get the star color from the NBAccent image in the nebula of the NB image where NO star is visible.

So it will not only color the stars available it will also "star color" parts of the image without stars. So same should apply for the area around stars since the NBAccent stars are bigger, especially if not shrinked, than the NB stars. So you should get "color halos" around the tight NB stars.

The resolution which is allowed in the forum makes it difficult to see if these problems are present in your images. I had this impression when I was trying this approach with my images.

But if it works for you, all fine Maybe I try it on my Wizard.

Regards
Stefan

[Carles]

Hi Stefan,

I don't understand your point with "NBAccent Stars" .. ? stars are from RGB, when you use NBAccent, the stars shouldn't get modified, if they do you should check the treshold.

What you mention on adding color where there is no star..that doesn't happen. Also I'm talking about using H-alpha file, not the whole NB file. Mainly because is not as clean and has less detail. Usually the cleaner channel is Halpha, cleaner as in less gradients more SNR and so on. So you can get details from it, then use the colour layer of the finished image.

Give it a go and let me know.

Carles.

[Stefan B]

I honestly don't know how to explain differently