M31: Study of core structues

[Rodd]

Long story short, I had used the TOA 130 and about 1.5 hours of 20 sec green subs to try and map dark structures in and around the core of M31.  I then inserted this data as a luminance into my HaLRGB image of M31 taken with the FSQ and .6x reducer.  Here are the results.  I had one with a little dimmer core, but I think this version picks up on the spherical nature of the structures more.--but its not as smooth.  What the heck--I will post both  I waffle back and forth.  Please disregard the artifacts apparent in the core--it was a tricky operation and I just couldn't fix everything

 

Brighter core

 

Original--dimmer core

[MarkAR]

Superb image, definitely got some dark swirls around the core I've not seen before.

[Rodd]

6 minutes ago, MarkAR said:

Superb image, definitely got some dark swirls around the core I've not seen before.

Thanks Mark--yes, they are extremely difficult to capture through the brightness of the core without resorting to some form of HDR integration, or what I have done....maybe its cheating?

Edited August 8, 2020 by Rodd

[MarkAR]

Not cheating at all, just using what equipment you have to best effect.

[ollypenrice]

Heh heh, the core of M31 is a barrel of laughs for the imager!  I think that, in the end, all who try end up in about the same position. Welcome to the club! Further penetration is going to need either new cameras or a radically different approach in processing - or both. What you have is good.

Olly

[Rodd]

1 hour ago, ollypenrice said:

Heh heh, the core of M31 is a barrel of laughs for the imager!  I think that, in the end, all who try end up in about the same position. Welcome to the club! Further penetration is going to need either new cameras or a radically different approach in processing - or both. What you have is good.

Olly

Thanks Olly.  It means a lot

[gorann]

As I said on Astrobin, I think you have teased out more details in there than I have seen before. HDR is not cheating - taming the dynamic range is the key to all processing. A linear version of M31 would be very uninteresting (or maybe interesting to see but rather ugly). Overall it is a great rendation of M31 Rodd!

Edited August 9, 2020 by gorann

[ollypenrice]

1 hour ago, gorann said:

 HDR is not cheating - taming the dynamic range is the key to all processing. A linear version of M31 would be very uninteresting (or maybe interesting to see but rather ugly). Overall it is a great rendation of M31 Rodd!

Not only is it not cheating, it's the whole point of this game in my view! The art of image processing can be summed up as the management of the data's brightness range.

Olly

[Macavity]

<wonders> Do classical imagers ever use the (post-processing) "contrasting mask" trick
--- or indeed "contast blending" of multiple exposures? A google search will reveal GIMP
methods for those. E.G. http://tir.astro.utoledo.edu/jdsmith/code/exposure_blend.php

Intrigued re. the "HDR techniques". (If ^^^ is "nonsense" excuse me... As you were! etc.) 🥳

[Rodd]

5 hours ago, gorann said:

As I said on Astrobin, I think you have teased out more details in there than I have seen before. HDR is not cheating - taming the dynamic range is the key to all processing. A linear version of M31 would be very uninteresting (or maybe interesting to see but rather ugly). Overall it is a great rendation of M31 Rodd!

 

3 hours ago, ollypenrice said:

Not only is it not cheating, it's the whole point of this game in my view! The art of image processing can be summed up as the management of the data's brightness range.

Olly

I did not mean HDR was cheating...I was kidding about my manual method being cheating (using different images for different parts of the image).  Believe it or not, but the grand old folks at Pixinsight would call that "painting".  They don't even think replacing targets in a wide field image with data collected at longer focal length is kosher....."painting".  I am sure they would think that I was morally bankrupt!

But I do have a question...why is there no color in the data I added as a luminance?  I added it the same way I always add luminance data--and color is never absent.    Maybe becuase the structures in question were not there at all in my color image?  

Edited August 9, 2020 by Rodd

[gorann]

23 minutes ago, Rodd said:

 

I did not mean HDR was cheating...I was kidding about my manual method being cheating (using different images for different parts of the image).  Believe it or not, but the grand old folks at Pixinsight would call that "painting".  They don't even think replacing targets in a wide field image with data collected at longer focal length is kosher....."painting".  I am sure they would think that I was morally bankrupt!

But I do have a question...why is there no color in the data I added as a luminance?  I added it the same way I always add luminance data--and color is never absent.    Maybe becuase the structures in question were not there at all in my color image?  

Yes, if there is no colour signal in the structures they will be B/W when you just add lum. You could try to stretch the RGB data to sea if you can find any structures before adding the lum (which was only from the green channel if I got you right).

[Rodd]

19 minutes ago, gorann said:

Yes, if there is no colour signal in the structures they will be B/W when you just add lum. You could try to stretch the RGB data to sea if you can find any structures before adding the lum (which was only from the green channel if I got you right).

Makes sense.....all the hornets are sleeping peacefully though, not sure I want to kick the nest.

[Mognet]

4 hours ago, Rodd said:

Makes sense.....all the hornets are sleeping peacefully though, not sure I want to kick the nest.

I don't think you need to. They are pretty amazing images as they are

[Rodd]

1 hour ago, Mognet said:

I don't think you need to. They are pretty amazing images as they are

Thank you.  That’s the trouble with electronic data.......you can always tinker

[Paul M]

That's a great piece of work!

There is a lot to take in. Need an atlas of M31 to take the full tour (which I'm googling right now)!

[Rodd]

3 minutes ago, Paul M said:

That's a great piece of work!

There is a lot to take in. Need an atlas of M31 to take the full tour (which I'm googling right now)!

Thanks Paul.  A big mosaic with a long focal length and full frame sensor is what is needed for that.  

[ian_bird]

On 09/08/2020 at 20:07, Paul M said:

Need an atlas of M31 to take the full tour (which I'm googling right now)!

Try this...

http://www.grinderphoto.se/images/m-31-2x2-mosaic.html

From the talented Jonas!

Cheers

Ian

[Rodd]

10 hours ago, ian_bird said:

Try this...

http://www.grinderphoto.se/images/m-31-2x2-mosaic.html

From the talented Jonas!

Cheers

Ian

Unbelievably awesome image.....The core could use some attention.  That would be even more amazing.

[Macavity]

Couldn't resist "a go" myself! I used part of an 8192 x 8192 TIFF from NAO:
https://www.noao.edu/image_gallery/html/im0424.html
I sense this is OK? Anyway, I'm reluctant to ruin play with SGLer's images! 😁

Sometimes *presentation* of data can emphasis a specific point! (or not?)

Wait for it... wait for it... 🥳


 

Edited August 18, 2020 by Macavity

[Rodd]

18 minutes ago, Macavity said:

I'm reluctant to ruin play with SGLer's images!

Fear not, I can ruin them all by myself!  Its called working them into the ground.  Anyway, the inverted image does reveal things that are easily missed in the regular image.