North American and Pelican Bicolor

[Rodd]

I was never able to render anything but a pink mess out of this data.  Televue np101is with .8x reducer, 14 30min Ha and 8 30 min OIII with STT 8300.

[alexbb]

This is great! Perhaps just a bit better star bloat control in the blue channel as in the red areas it's visible.

[michael.h.f.wilkinson]

Really lovely detail in that shot

[Rodd]

42 minutes ago, moise212 said:

This is great! Perhaps just a bit better star bloat control in the blue channel as in the red areas it's visible.

Thanks Alex.  Yeah....this was a quickie.....Wasn't sure it was worth giving it the full treatment.    The stars are on my list

Rodd

[Rodd]

32 minutes ago, michael.h.f.wilkinson said:

Really lovely detail in that shot

Thanks Michael.

Rodd

[tooth_dr]

Very nice Rodd, the blue colour is especially nice.

[graemlourens]

Hi Rodd.

I definitively would go for the 'extended' processing on this one!

It doesn't come every day that you have a target with so much detail and so much data in general. I think its already a great image, i'd control the blue more though. Stars but also the other blue parts seem over-vibrated. The Pink can be treated in PI with selective colour adjustments, but Bi-Color tends to be somewhat pink especially if you only take HA as LUM (did you?)

Kind regards, Graem

[Rodd]

1 hour ago, tooth_dr said:

Very nice Rodd, the blue colour is especially nice.

Thanks Doc.  the blue was what was lacking in my previous attempts.

Rodd

[Rodd]

1 hour ago, graemlourens said:

Hi Rodd.

I definitively would go for the 'extended' processing on this one!

It doesn't come every day that you have a target with so much detail and so much data in general. I think its already a great image, i'd control the blue more though. Stars but also the other blue parts seem over-vibrated. The Pink can be treated in PI with selective colour adjustments, but Bi-Color tends to be somewhat pink especially if you only take HA as LUM (did you?)

Kind regards, Graem

Thanks Graem.  Yes--the saturation is to high--I was careless.  As far as lum--I used Ha for red and then inserted as lum.

Rodd

[wimvb]

Great image with lots of detail. what does the bi-colour look like without Ha as luminance?

I think you have posterisation in the dark nebula that forms the "Gulf of Mexico", making it rather solid. This target is extremely difficult to render naturally. One of the images that comes close is in this post:

https://pixinsight.com/forum/index.php?topic=6316.0

 

[Rodd]

1 hour ago, wimvb said:

Great image with lots of detail. what does the bi-colour look like without Ha as luminance?

I think you have posterisation in the dark nebula that forms the "Gulf of Mexico", making it rather solid. This target is extremely difficult to render naturally. One of the images that comes close is in this post:

https://pixinsight.com/forum/index.php?topic=6316.0

 

Thanks Wim.  Too much green for me in that one.  But I do like the dustiness.  Here is a more natural look I think, not as saturated in blue--but enough to overcome looking gray, I hope.  I have controlled the stars as best I can--still a slight extended halo around 1 in the body of the Pterodactyl.  But not too bad.  Gulf of mexio has some structure now.  I am beginning to feel the itch to go at this one again and get much more data--with a wider FOV and higher resolution.

 

 

[Rodd]

or with a bit more snap to it

 

[wimvb]

The framing as it is, makes this image all about the dark nebula in front of the Ha/O regions. But it's very difficult to bring this out in processing. Your new version already looks a lot better. Btw, I also love the glow in the Pterodactyl's neck.

Normally, the NA and Pelican are viewed as two bright nebulae on a dark background. But try to view this image as one bright nebula (such as the Rosetta nebula, or the Heart nebula) with a dark dust cloud in front of it, dividing it in two parts. This may be easier to do with the wide field image in my reference than with your image.

The image I referred to comes with variations, one with the green removed ( https://mtanous.files.wordpress.com/2013/11/ngc7000_hst_no_green.jpg ). But it was more about the dustiness than the colour.

46 minutes ago, Rodd said:

I am beginning to feel the itch to go at this one again and get much more data--with a wider FOV and higher resolution.

That could become a truely amazing image. This target benefits from a wider field.

Btw, your image has a narrow blue edge near the upper right corner. The easiest way to get rid of this is to crop the image before saving for publication.

[Rodd]

27 minutes ago, wimvb said:

The framing as it is, makes this image all about the dark nebula in front of the Ha/O regions. But it's very difficult to bring this out in processing. Your new version already looks a lot better. Btw, I also love the glow in the Pterodactyl's neck.

Normally, the NA and Pelican are viewed as two bright nebulae on a dark background. But try to view this image as one bright nebula (such as the Rosetta nebula, or the Heart nebula) with a dark dust cloud in front of it, dividing it in two parts. This may be easier to do with the wide field image in my reference than with your image.

The image I referred to comes with variations, one with the green removed ( https://mtanous.files.wordpress.com/2013/11/ngc7000_hst_no_green.jpg ). But it was more about the dustiness than the colour.

That could become a truely amazing image. This target benefits from a wider field.

Btw, your image has a narrow blue edge near the upper right corner. The easiest way to get rid of this is to crop the image before saving for publication.

OK--have to stop now.  One more for the record--a bit of golden sunshine into the mix.  Sort of mimics SII......hmm

 

[wimvb]

Wow, a vast improvement over the first version. Toned down colours, and a much fluffier dark nebula. Adding Sii will give you a more traditional sho palette. But I like it very much as it is.

[Rodd]

15 minutes ago, wimvb said:

Wow, a vast improvement over the first version. Toned down colours, and a much fluffier dark nebula. Adding Sii will give you a more traditional sho palette. But I like it very much as it is.

Thanks Wim.  lately I lean toward LRGB (except when the Moon forces me to shoot NB--which was my first love).  So maybe am HaLRGB version.  

Rodd

[gorann]

Had not seen this thread until now. Really great image Rodd, especially the last version! I am always amazed how different these objects look in NB compared to RGB. In RGB that dark nebulosity looks like dark sky background. I assume that the NB image reveals that it is really dark stuff and not sky.

Some words from the nasty perfectionist in me: I assume you have done your best to remove the blue or gray halos around the stars. Are they caused by using Ha only as Lum? There is also a blue streak along the upper right edge of the image that could be cropped away of maybe even fixed.

 

[Rodd]

7 minutes ago, gorann said:

Had not seen this thread until now. Really great image Rodd, especially the last version! I am always amazed how different these objects look in NB compared to RGB. In RGB that dark nebulosity looks like dark sky background. I assume that the NB image reveals that it is really dark stuff and not sky.

Some words from the nasty perfectionist in me: I assume you have done your best to remove the blue or gray halos around the stars. Are they caused by using Ha only as Lum? There is also a blue streak along the upper right edge of the image that could be cropped away of maybe even fixed.

 

Thanks Gorann.  This is old data--so I am not sure about allot of things.  The blue halos were made much worse when I boosted saturation.  I can live with them at this extent--kind of have to look for them at full resolution to really see them,  The blue streak I just realized is a cropping error--my crop was not quite enough to remove the blackened edge on the Ha master.  Cropping is the only option at this point.  I think I am planning to hit this target with the FSQ at F3--which will give me all of the NA and Pelican and some of the regions below, with a resolution higher than this image (still hard for me to get my mind around...the wonders of small pixels).  Should be interesting.  Debating on RGB or NB.  The Moon is up big time now and skies are supposed top be clear for the next 2-3 days--so NB it is.  This is a bright target so I should be OK.

Rodd

[gorann]

The best of luck Rodd!

[wimvb]

2 hours ago, gorann said:

In RGB that dark nebulosity looks like dark sky background.

I believe that the NA and Pelican nebulae are actually parts of one and the same vast emission nebula, with bright young stars that have swept away much of the gas in the area. The dark patches between the NA and Pelican are a dark nebula that obscures the central part of this complex. It's probably the limited dynamic range of dslr cameras that makes it difficult to show the dark nebula in all its glory. What you end up with is posterization.

[Rodd]

1 minute ago, wimvb said:

I believe that the NA and Pelican nebulae are actually parts of one and the same vast emission nebula, with bright young stars that have swept away much of the gas in the area. The dark patches between the NA and Pelican are a dark nebula that obscures the central part of this complex. It's probably the limited dynamic range of dslr cameras that makes it difficult to show the dark nebula in all its glory. What you end up with is posterization.

Could you define pasteurization?  Not really sure what it is exactly

Rodd

[wimvb]

Posterization is the effect of intensity levels being discrete rather than continuous. Eg, with 8 bit data there are 256 intensity levels. A dark nebula may have intensity values of 1, 2, 3. If you stretch the image, the steps between various intensity values become visible. This is posterization. Most ccd cameras have a dynamic range of 12 - 14 bit, even if the data is 16 bit. Dslr cameras, at high ISI, have a smaller dynamic range. It can even drop below 8 bit.

[Rodd]

9 minutes ago, wimvb said:

Posterization is the effect of intensity levels being discrete rather than continuous. Eg, with 8 bit data there are 256 intensity levels. A dark nebula may have intensity values of 1, 2, 3. If you stretch the image, the steps between various intensity values become visible. This is posterization. Most ccd cameras have a dynamic range of 12 - 14 bit, even if the data is 16 bit. Dslr cameras, at high ISI, have a smaller dynamic range. It can even drop below 8 bit.

Ah--so more data is better even if you can't really see it

Rodd

[gorann]

I also noticed the posterization in the first version but it looked better in the last. It is something to be aware of when stretching images. At least in PS the curves function works only in 256 levels (2 to the power of 8 ) so it is important to make many small stretches not to loose dynamic range as the original 16 bit image contains much more than 256 levels (actually 2 to the power of 16 so 65536 levels). I usually do about 10 iterations of stretching. Not sure how PI works here. By the way Rodd, this is posterization (the name coming from its use in posters, particularly by An Warhol):

[tooth_dr]

55 minutes ago, Rodd said:

Could you define pasteurization? 

Rodd

Next time you pour some milk in your tea have a read at the label ?