ASTRO:M94

I had to work quite hard to show both the core of M94 and the halo, the
result looks a bit more washed out than I would like it to be. The outer
"ring" is visible in the raw images with a hard stretch, but I didn't manage
to preserve it in the final picture.

Taken from the middle of Berlin with an 8" SCT at f/6.5, G11 mount, SXV-H9
camera, 45x150 seconds.

The picture can also be found at
http://ccd-astronomy.de/temp/m94-45x150gut.jpg

Stefan

And here is a version that has slightly more contrast (less logarithmic
stretch).

Stefan

"Stefan Lilge" schrieb im Newsbeitrag
...
I had to work quite hard to show both the core of M94 and the halo, the
result looks a bit more washed out than I would like it to be. The outer
"ring" is visible in the raw images with a hard stretch, but I didn't
manage
to preserve it in the final picture.

Taken from the middle of Berlin with an 8" SCT at f/6.5, G11 mount, SXV-H9
camera, 45x150 seconds.

The picture can also be found at
http://ccd-astronomy.de/temp/m94-45x150gut.jpg

Stefan

Stefan Lilge wrote:

And here is a version that has slightly more contrast (less logarithmic
stretch).

Stefan

"Stefan Lilge" schrieb im Newsbeitrag
...

I had to work quite hard to show both the core of M94 and the halo, the
result looks a bit more washed out than I would like it to be. The outer
"ring" is visible in the raw images with a hard stretch, but I didn't
manage
to preserve it in the final picture.

Taken from the middle of Berlin with an 8" SCT at f/6.5, G11 mount,
SXV-H9
camera, 45x150 seconds.

The picture can also be found at
http://ccd-astronomy.de/temp/m94-45x150gut.jpg

Stefan


------------------------------------------------------------------------

M94 is certainly an image processing nightmare. You compound the
problem imaging from Berlin. That would be fatal to me. It came out
quite well.

My solution in Photoshop was to first process the whole image for the
core of the galaxy. Then I selected the area about half way out from
the edge of the bright nucleus out beyond the outer faint ring using
feather that would include into the edge of the bright spiral part.
Then I enhance that part of the image. That leaves the core detail
untouched as well as the stars beyond the galaxy. Then I select the
faint outer ring again with a large feather to include the very outer
parts of the large disk. That is then enhanced without further hurting
the rest of the image. Problem is that at the start you have to know
where that outer ring ends and that can't easily be determined. I had
to do it several times before I found the edge. It went out farther
than I realized.

Most photoshop experts use two different exposures, one for the core and
one for the fainter areas. Using masks they blend the two. I'm not
able to make that work as yet so use the "ring" method. Photoshop gives
several ways of selecting these areas. You can use an oval tool that
works well in this case, or you can lasso the area by following a line
of equal intensity though this usually has to be edited a bit as it
often goes astray on me. Often I just draw the area with the mouse
using a different lasso tool. By defining overlapping areas for
different processing it all blends seamlessly when you are done. This
prevents the "flat" brighter area problem you mention. I don't know if
AstroArt has something equivalent or not.

This is one of the things I'm doing when reprocessing my last year shots
during this horrid spell of weather. Clouds for days on end with only
one good day of rain in two months. We need the rain as things are
super dry here. You can walk across my bog without getting your feet
wet. Wetland creatures are dying off in great numbers. The only good
thing is this includes mosquitos! A pond I drive past on the way out is
virtually dry. I've never seen it less than 4 to 5 foot deep before, now
it is just mud. Normally it is home to a family of loons and lots of
ducks and geese. The beaver froze out last winter when the pond got too
shallow for them to get out of their lodge. Clouds with no rain is a
really nasty situation for everyone. Though it was sort of clear for 2
hours last night so I now have something new to try and process.

Rick


--
Correct domain name is arvig and it is net not com. Prefix is correct.
Third character is a zero rather than a capital "Oh".

That is nice detail Stefan... I need to re-do my version to see if I can
record that core area better.... nice and smooth but it has a very black
background on my monitor.

--
Regards, Doug W.
www.photonsfate.com
"Stefan Lilge" wrote in message
...
I had to work quite hard to show both the core of M94 and the halo, the
result looks a bit more washed out than I would like it to be. The outer
"ring" is visible in the raw images with a hard stretch, but I didn't
manage
to preserve it in the final picture.

Taken from the middle of Berlin with an 8" SCT at f/6.5, G11 mount, SXV-H9
camera, 45x150 seconds.

The picture can also be found at
http://ccd-astronomy.de/temp/m94-45x150gut.jpg

Stefan

Very nice detail in this image Stefan, beatiful !!

greetz
Erik bryssinck

Hey stefan, some nice shots you have here.. also done a lot of processing
lately i see.
Number of clear nights is quite terrible this year, we had some here last
night.
alle going well there?

reg
Dirk

--
Dirk van den Herik

A journey of thousand lightyears
starts with the first step.
"Stefan Lilge" wrote in message
...
I had to work quite hard to show both the core of M94 and the halo, the
result looks a bit more washed out than I would like it to be. The outer
"ring" is visible in the raw images with a hard stretch, but I didn't
manage
to preserve it in the final picture.

Taken from the middle of Berlin with an 8" SCT at f/6.5, G11 mount, SXV-H9
camera, 45x150 seconds.

The picture can also be found at
http://ccd-astronomy.de/temp/m94-45x150gut.jpg

Stefan