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ASTRO: NGC 2903



 
 
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  #1  
Old April 5th 07, 07:06 PM posted to alt.binaries.pictures.astro
D van den H
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Posts: 35
Default ASTRO: NGC 2903

Hello again,
NGC 2903
29 x 60 sec
No filters
10"SCT
No autoguiding
Home build CCD camera at -22degr C
Dark's used en MAXIMDL en CS2 processed.

Thx for looking,
Dirk
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  #2  
Old April 5th 07, 09:23 PM posted to alt.binaries.pictures.astro
Rick Johnson[_2_]
external usenet poster
 
Posts: 3,085
Default ASTRO: NGC 2903



D van den H wrote:
Hello again,
NGC 2903
29 x 60 sec
No filters
10"SCT
No autoguiding
Home build CCD camera at -22degr C
Dark's used en MAXIMDL en CS2 processed.

Thx for looking,
Dirk

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


This one has a bright core that takes careful use of Curves in Photoshop
to preserve the detail. It looks like the detail is there, just that in
adding the images together or in processing the histogram got severely
cut off at the top. 60 second exposures wouldn't over expose the
nucleus. Though a straight adding of 29 might. Add is fine if your
software supports 32 bit adds and converts back to 16 without lopping
off the top end.

My shot is still on the usenet archive page:
http://www.usenet-replayer.com/5/4/0...059045.21.jpeg
and was made from 300 second shots. I combined them using an average
type combine that also rejects noise (Sigma Reject) then moved them into
Photoshop using FITS Liberator (free program). I did no processing
there setting the low point to 100 (My system has a 100 unit starting
point) and 65535 for the high and leaving it linear. Then moved it in
to Photoshop, flipped it vertically (FITS Liberator has the nasty habit
of flipping (not rotating) the image so you have to unflip it first
thing. Then I used curves many time to bring up the image. With some
galaxies you may have to select the core with a large feather then
invert the selection. Then you can bring up the arms without the core
burning out. Then invert the selection again to process the core so the
two blend together smoothly. Think that's what I did with my lum image
as well as the RGB one that was then combined with it to make the color
image.

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".

  #3  
Old April 5th 07, 09:41 PM posted to alt.binaries.pictures.astro
D van den H
external usenet poster
 
Posts: 35
Default ASTRO: NGC 2903

Thx Rick, i will play around with it.
If i look at the original single shots the core has good details.
I will experiment with it and will present the result here.
Thx again for the hints.

dirk

"Rick Johnson" wrote in message
...


D van den H wrote:
Hello again,
NGC 2903
29 x 60 sec
No filters
10"SCT
No autoguiding
Home build CCD camera at -22degr C
Dark's used en MAXIMDL en CS2 processed.
Thx for looking,
Dirk

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


This one has a bright core that takes careful use of Curves in Photoshop
to preserve the detail. It looks like the detail is there, just that in
adding the images together or in processing the histogram got severely cut
off at the top. 60 second exposures wouldn't over expose the nucleus.
Though a straight adding of 29 might. Add is fine if your software
supports 32 bit adds and converts back to 16 without lopping off the top
end.

My shot is still on the usenet archive page:
http://www.usenet-replayer.com/5/4/0...059045.21.jpeg
and was made from 300 second shots. I combined them using an average type
combine that also rejects noise (Sigma Reject) then moved them into
Photoshop using FITS Liberator (free program). I did no processing there
setting the low point to 100 (My system has a 100 unit starting point) and
65535 for the high and leaving it linear. Then moved it in to Photoshop,
flipped it vertically (FITS Liberator has the nasty habit of flipping (not
rotating) the image so you have to unflip it first thing. Then I used
curves many time to bring up the image. With some galaxies you may have
to select the core with a large feather then invert the selection. Then
you can bring up the arms without the core burning out. Then invert the
selection again to process the core so the two blend together smoothly.
Think that's what I did with my lum image as well as the RGB one that was
then combined with it to make the color image.

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".



  #4  
Old April 5th 07, 09:56 PM posted to alt.binaries.pictures.astro
Rick Johnson[_2_]
external usenet poster
 
Posts: 3,085
Default ASTRO: NGC 2903

Just noticed it is a home made camera. I was assuming a 16 commercial
camera. If it is a 12 bit camera it might be a bit tight but think
there's more detail to be found there even that that's the case.

Rick

D van den H wrote:

Thx Rick, i will play around with it.
If i look at the original single shots the core has good details.
I will experiment with it and will present the result here.
Thx again for the hints.

dirk

"Rick Johnson" wrote in message
...


D van den H wrote:

Hello again,
NGC 2903
29 x 60 sec
No filters
10"SCT
No autoguiding
Home build CCD camera at -22degr C
Dark's used en MAXIMDL en CS2 processed.
Thx for looking,
Dirk

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


This one has a bright core that takes careful use of Curves in Photoshop
to preserve the detail. It looks like the detail is there, just that in
adding the images together or in processing the histogram got severely cut
off at the top. 60 second exposures wouldn't over expose the nucleus.
Though a straight adding of 29 might. Add is fine if your software
supports 32 bit adds and converts back to 16 without lopping off the top
end.

My shot is still on the usenet archive page:
http://www.usenet-replayer.com/5/4/0...059045.21.jpeg
and was made from 300 second shots. I combined them using an average type
combine that also rejects noise (Sigma Reject) then moved them into
Photoshop using FITS Liberator (free program). I did no processing there
setting the low point to 100 (My system has a 100 unit starting point) and
65535 for the high and leaving it linear. Then moved it in to Photoshop,
flipped it vertically (FITS Liberator has the nasty habit of flipping (not
rotating) the image so you have to unflip it first thing. Then I used
curves many time to bring up the image. With some galaxies you may have
to select the core with a large feather then invert the selection. Then
you can bring up the arms without the core burning out. Then invert the
selection again to process the core so the two blend together smoothly.
Think that's what I did with my lum image as well as the RGB one that was
then combined with it to make the color image.

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".






 




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