ASTRO: Pillars up close and personal

I took a detailed crop from the center of my highest resolution source image
and made this:

you can also see it he

http://www.narrowbandimaging.com/m16...2hao3_page.htm

http://www.narrowbandimaging.com/ima...3_29x20min.jpg

Nice Richard!
What is the reason that all your star images are pink? is it processing or
also in the raw images?

Reg
Dirk

--
Dirk van den Herik

A journey of thousand lightyears
starts with the first step.
"Richard Crisp" wrote in message
t...
I took a detailed crop from the center of my highest resolution source
image
and made this:

you can also see it he

http://www.narrowbandimaging.com/m16...2hao3_page.htm

http://www.narrowbandimaging.com/ima...3_29x20min.jpg

the hubble image has the same effect Dirk

http://hubblesite.org/newscenter/arc...mat/large_web/

it is an artifact of the processing: the sulfur is too weak compared to the
hydrogen so when you stretch it the stars get fat in the sulfur channel


"DvandenH" wrote in message
el.net...
Nice Richard!
What is the reason that all your star images are pink? is it processing or
also in the raw images?

Reg
Dirk

--
Dirk van den Herik

A journey of thousand lightyears
starts with the first step.
"Richard Crisp" wrote in message
t...
I took a detailed crop from the center of my highest resolution source
image
and made this:

you can also see it he

http://www.narrowbandimaging.com/m16...2hao3_page.htm

http://www.narrowbandimaging.com/ima...3_29x20min.jpg

Oke, never noticed it Richard..

reg
Dirk

--
Dirk van den Herik

A journey of thousand lightyears
starts with the first step.
"Richard Crisp" wrote in message
...
the hubble image has the same effect Dirk

http://hubblesite.org/newscenter/arc...mat/large_web/

it is an artifact of the processing: the sulfur is too weak compared to
the hydrogen so when you stretch it the stars get fat in the sulfur
channel


"DvandenH" wrote in message
el.net...
Nice Richard!
What is the reason that all your star images are pink? is it processing
or also in the raw images?

Reg
Dirk

--
Dirk van den Herik

A journey of thousand lightyears
starts with the first step.
"Richard Crisp" wrote in message
t...
I took a detailed crop from the center of my highest resolution source
image
and made this:

you can also see it he

http://www.narrowbandimaging.com/m16...2hao3_page.htm

http://www.narrowbandimaging.com/ima...3_29x20min.jpg

really i tend to think that they arise from aggressive stretching. the
sulfur isn't as strong as the hydrogen so i have to stretch it more to get a
decent extent of my data histogram.

when you stretch the images the stars get brighter and fatter and it is the
"base" of the star that causes the halo

i think the fix would be to have a passband that is narrower for the sulfur
and or oxygen because the wider the passband the more starlight is passed.

so by having less starlight making it through in relation to the nebular
light, I believe post-stretch the star diameters may match more closely

some objects have stronger sulfur than does M16 and on those this isn't
observed to the same degree.

I am reasonably confident it is the mechanism I just described.

there are processing tricks that can be done, but I personally don't like to
do that sort of editing. Besides being tedious it transcends an ethics issue
that I don't want to address: I prefer to keep things a bit more honest than
copying and pasting stars from another image atop these as I have seen other
imagers do. For me the stars are a nuisance I'd prefer to not see in the
image anyway, since I like the nebulosity the best, but are handy to
optimize focus, guide and so on :-)


"DvandenH" wrote in message
bel.net...
Oke, never noticed it Richard..

reg
Dirk

--
Dirk van den Herik

A journey of thousand lightyears
starts with the first step.
"Richard Crisp" wrote in message
...
the hubble image has the same effect Dirk

http://hubblesite.org/newscenter/arc...mat/large_web/

it is an artifact of the processing: the sulfur is too weak compared to
the hydrogen so when you stretch it the stars get fat in the sulfur
channel


"DvandenH" wrote in message
el.net...
Nice Richard!
What is the reason that all your star images are pink? is it processing
or also in the raw images?

Reg
Dirk

--
Dirk van den Herik

A journey of thousand lightyears
starts with the first step.
"Richard Crisp" wrote in message
t...
I took a detailed crop from the center of my highest resolution source
image
and made this:

you can also see it he

http://www.narrowbandimaging.com/m16...2hao3_page.htm

http://www.narrowbandimaging.com/ima...3_29x20min.jpg