jase
29-01-2008, 06:01 AM
Hi All,
Well, not as active in the imaging scene as I’d like. Work is keeping me extremely busy (I liken it to “organised chaos”). Will do my best to get online when possible. Anyway, I’m pleased to present my latest effort, IC2177 - The Seagull Nebula (http://www.cosmicphotos.com/gallery/image.php?fld_image_id=130&fld_album_id=11).
Soaring the night skies, the Seagull is a massive diffused nebula that flies the border of the constellations Monoceros and Canis Major. The head of the Seagull (NGC2327), displays an interesting dark lane of nebulosity that resembles a lightning bolt. The surrounding nebulosity is a magenta/blue hue due to the high volume of dust which reflects the blue light of the embedded stars. This is also seen on tip of the upper wing. The Seagull Nebula is approximately 1,800 light years away.
About the image;
The image is a [L]+[Ha+R]GB composition totalling 7.5 hours (L:60mins; Ha:120mins; R: 90mins; G:90mins; B:90mins) using 15min subs. MaximDL used for reduction/calibration (bias/dark/flats/hot&dead pixel removal) and combine (using Russ Croman’s Sigma Reject). Subs registered in Registar.
Didn’t do anything special in processing this target – wanted to simply ensure I was still “capable” of image processing considering I’d been out of action for a while. I did however experiment with what I call “SoftLight cascading” (others may call it something else). In PS, when you create/duplicate multiple chrominance layers (blended as SoftLight), they colour gets progressively richer (when managed/stacked correctly). I think a better method is to used DDP and then heavily saturate the chrominance before integrating it as a softlight blend in PS – similar to what RJ GaBany and Rob Gendler use to obtain colour depth. Still, I enjoy experimenting to determine what is possible in PS. I feel certain I only use 30% of what PS is capable of. I used Neat Image as a PS plugin for two iterations to reduce noise in the dim areas. I experienced an interesting image calibration problem with the bias frames on this image. When the bias frames where applied to the Ha subs, the data became black clipped. I’ve seen this happen before, but couldn’t recall what I did in the past. Thought it may have been something to do with the pedestal value so I manually calibrated the Ha subs. Certainly not optimal (and caused additional work), but the result speaks for itself. Personally, I think this image screams for more data, in particular Ha and believe the chrominance maybe too rich, though it certainly accentuated the lovely star field. For now, it will suffice. The image has been reduced by 70% for web presentation.
Enough bantering… Hope you enjoy it. As always, all comments welcome.:)
Cheers
Well, not as active in the imaging scene as I’d like. Work is keeping me extremely busy (I liken it to “organised chaos”). Will do my best to get online when possible. Anyway, I’m pleased to present my latest effort, IC2177 - The Seagull Nebula (http://www.cosmicphotos.com/gallery/image.php?fld_image_id=130&fld_album_id=11).
Soaring the night skies, the Seagull is a massive diffused nebula that flies the border of the constellations Monoceros and Canis Major. The head of the Seagull (NGC2327), displays an interesting dark lane of nebulosity that resembles a lightning bolt. The surrounding nebulosity is a magenta/blue hue due to the high volume of dust which reflects the blue light of the embedded stars. This is also seen on tip of the upper wing. The Seagull Nebula is approximately 1,800 light years away.
About the image;
The image is a [L]+[Ha+R]GB composition totalling 7.5 hours (L:60mins; Ha:120mins; R: 90mins; G:90mins; B:90mins) using 15min subs. MaximDL used for reduction/calibration (bias/dark/flats/hot&dead pixel removal) and combine (using Russ Croman’s Sigma Reject). Subs registered in Registar.
Didn’t do anything special in processing this target – wanted to simply ensure I was still “capable” of image processing considering I’d been out of action for a while. I did however experiment with what I call “SoftLight cascading” (others may call it something else). In PS, when you create/duplicate multiple chrominance layers (blended as SoftLight), they colour gets progressively richer (when managed/stacked correctly). I think a better method is to used DDP and then heavily saturate the chrominance before integrating it as a softlight blend in PS – similar to what RJ GaBany and Rob Gendler use to obtain colour depth. Still, I enjoy experimenting to determine what is possible in PS. I feel certain I only use 30% of what PS is capable of. I used Neat Image as a PS plugin for two iterations to reduce noise in the dim areas. I experienced an interesting image calibration problem with the bias frames on this image. When the bias frames where applied to the Ha subs, the data became black clipped. I’ve seen this happen before, but couldn’t recall what I did in the past. Thought it may have been something to do with the pedestal value so I manually calibrated the Ha subs. Certainly not optimal (and caused additional work), but the result speaks for itself. Personally, I think this image screams for more data, in particular Ha and believe the chrominance maybe too rich, though it certainly accentuated the lovely star field. For now, it will suffice. The image has been reduced by 70% for web presentation.
Enough bantering… Hope you enjoy it. As always, all comments welcome.:)
Cheers