Another distorted Southern Spiral Galaxy repro

gregbradley · #1 23-02-2014, 09:29 AM

NGC1808. Not often imaged but its quite a bright galaxy. Part of my ongoing Galaxy image series.

It has an odd shape - part spiral, part elliptical or are those tidal streams from an earlier interaction?

Thanks for the constructive criticism. I did a repro using the Lab colour channel technique from Louie and R Jay Gabany to bring out the colour.

CDK17, Trius 694, PME.
9 hours 20 minutes.

http://upload.pbase.com/gregbradley/...54574611/large regular size

http://upload.pbase.com/gregbradley/...74611/original large size

Greg

allan gould · #2 23-02-2014, 10:42 AM

Very nice image Greg, we must have the same list but different weather. Damn these clouds.
Allan

alpal · #3 23-02-2014, 10:45 AM

Nice work Greg,
you got those galaxy arms very well.
I think I better delete my effort on flickr photos.

I had a bit of a play with your pic - I hope you don't mind?
This is a bit overdone & needs masking.
What about if you increased the colour using LAB mode like this:

cheers
Allan

allan gould · #4 23-02-2014, 11:16 AM

Great repro Allan - must look at LAB colour procedure. Do you have a link?
Allan

alpal · #5 23-02-2014, 11:21 AM

Quote:

Originally Posted by allan gould

Great repro Allan - must look at LAB colour procedure. Do you have a link?
Allan

Thanks - one of Louie's many videos, see here:

http://www.youtube.com/watch?v=fE2GS_87Ct8

The idea is that you can adjust/boost the colours without changing the brightness.

glenc (Glen) · #6 23-02-2014, 11:22 AM

That is an amazingly sharp and deep image Greg.
It is also great to see another image of a James Dunlop galaxy.
He found 50 southern galaxies in 1826 with the equivalent of a 6" reflector.
https://picasaweb.google.com/1100488...2146/Dunlop28#

RickS (Rick) · #7 23-02-2014, 11:58 AM

Great details and a really nice galaxy image, Greg! Colour a little muted for my taste too.

Cheers,
Rick.

atalas · #8 23-02-2014, 12:14 PM

Lovely galaxy with great detail Greg!well done dude.

gregbradley · #9 23-02-2014, 12:35 PM

Quote:

Originally Posted by allan gould

Very nice image Greg, we must have the same list but different weather. Damn these clouds.
Allan

Must be! There have been quite a few nice galaxies to target in the last few months. I am not sure there are as many coming up but I hope so.

Quote:

Originally Posted by alpal

Nice work Greg,
you got those galaxy arms very well.
I think I better delete my effort on flickr photos.

I had a bit of a play with your pic - I hope you don't mind?
This is a bit overdone & needs masking.
What about if you increased the colour using LAB mode like this:

cheers
Allan

Don't be silly Allan your image is great. You have to keep in mind the equipment being used. You would expect a deeper result from the CDK.

Gee I don't normally like repros but that does look nice. Star mask to protect the stars and some nice colour. Time for a repro already!

Not sure why the colour didn't come out in the first place. Is this R Jay Lab Colour technique?

Quote:

Originally Posted by allan gould

Great repro Allan - must look at LAB colour procedure. Do you have a link?
Allan

Quote:

Originally Posted by RickS

Great details and a really nice galaxy image, Greg! Colour a little muted for my taste too.

Cheers,
Rick.

Yes after seeing Allan's lab colour boost I agree. I thought it was just a plain coloured galaxy. There aren't many examples of it to compare.

Quote:

Originally Posted by atalas

Lovely galaxy with great detail Greg!well done dude.

Cheers Louie. Repro coming up though!

Greg

gregbradley · #10 23-02-2014, 12:40 PM

Quote:

Originally Posted by glenc

That is an amazingly sharp and deep image Greg.
It is also great to see another image of a James Dunlop galaxy.
He found 50 southern galaxies in 1826 with the equivalent of a 6" reflector.
https://picasaweb.google.com/1100488...2146/Dunlop28#

Thanks Glen. I have been putting more attention on sharpening and deconvolution in my galaxy images. Its another advantage of the small pixels of the 694 chip. Images take a lot more decon than with KAF8300 or KAF16803 images before showing artifacts. Same with sharpening. I guess that is the extra resolution from small pixels.

What got lost a little that shows up in the luminance is the "core" is really about 5 or 6 bright areas a bit like looking at the Trapezium stars in Orion Neb. I saw a similar core in another galaxy I imaged lately. Interesting. I seem to recall reading an article about some globs orbiting Sag A in the Milky Way close in. Its a fairly recent discovery. I wonder if these bright spots at the core at large globs circling the black hole?

Greg.

RickS (Rick) · #11 23-02-2014, 01:23 PM

Quote:

Originally Posted by gregbradley

Is this R Jay Lab Colour technique?

It's one that he mentions.

The technique is pretty well known, at least to people who dabble with LAB colour. It's the first technique introduced in the book I have been reading: "Photoshop LAB Color - the Canyon Conundrum and Other Adventures in the Most Powerful Colorspace" by Dan Margulis.

nebulosity. (Jo) · #12 23-02-2014, 01:58 PM

Another awesome image Greg, looking forward to the repro

Cheers
Jo

gregbradley · #13 23-02-2014, 03:07 PM

Quote:

Originally Posted by nebulosity.

Another awesome image Greg, looking forward to the repro

Cheers
Jo

Thanks Jo Repro is now done, the same links in the original post.

Greg.

alpal · #14 23-02-2014, 04:29 PM

Good work - & I like the detail & colours that have popped out.

gregbradley · #15 23-02-2014, 05:50 PM

Quote:

Originally Posted by alpal

Good work - & I like the detail & colours that have popped out.

Thanks Allan and thanks for the tip.

Greg.

SkyViking (Rolf) · #16 23-02-2014, 06:37 PM

Nice image of yet another interesting galaxy! It seems to have a very prominent population of blue stars along the upper side. Thanks for the view

Shiraz (Ray) · #17 23-02-2014, 07:24 PM

that's a cracker of an image Greg - really nice in all respects.

gregbradley · #18 23-02-2014, 09:31 PM

Quote:

Originally Posted by SkyViking

Nice image of yet another interesting galaxy! It seems to have a very prominent population of blue stars along the upper side. Thanks for the view

Thanks Rolf. Yes it does seem to have the blue stars on one side. Perhaps a consequence of whatever caused the big loop.

Quote:

Originally Posted by Shiraz

that's a cracker of an image Greg - really nice in all respects.

Thanks Ray. Galaxy processing has its own workflow compared to other objects. Getting it together step by step.

Greg.

marc4darkskies (Marcus) · #19 23-02-2014, 09:55 PM

Nice work Greg!

An interesting galaxy. You've managed to pull out some great detail there!

Cheers, Marcus

gregbradley · #20 23-02-2014, 10:52 PM

Quote:

Originally Posted by marc4darkskies

Nice work Greg!

An interesting galaxy. You've managed to pull out some great detail there!

Cheers, Marcus

Thanks Marcus. Multiple level decon helped get more detail.
Looking forward to your first light. The cloudy weather lately must have you chomping at the bit!

Greg.