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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 |
#2
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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
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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
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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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