jase
20-05-2010, 03:03 PM
Hi All,
Have not produced an image with the "local" gear for well over five months. Feels like all I've done is capture data night after night with no result to show...especially considering the initial intent was to perform a quick test with the new camera. Alas, I got carried away and ended up with a long duration imaging project. When I first joined the IIS community, Glen (Glenc) provided a challenge if I could image an area across from Eta. For the life of me, I can't remember which direction from Eta was requested...so I hope this will suffice given its taken a few years to get this far! Apologies Glen! :)
So without further ado, I pleased to present Environs of the Hibiscus (http://cosmicphotos.com/gallery/image.php?fld_image_id=210&fld_album_id=9).
Warning - large resolutions may take time to load.
Wha?! the Hibiscus?! :screwy: Green thumb eh?
Scene description;
The southern sky in the constellations Crux and Carina is filled with an entourage of impressive deep sky delights. In the image presented above, from left to right is IC2944 the Running Chicken Nebula, NGC3576 at center followed by the large nebula complex of NGC3372 more commonly known as the Eta Carina Nebula. Numerous star clusters also scatter the field. Wide field panoramas such as this, Eta Carina takes on the appearance of a Hibiscus flower. Lush petals produced by blue oxygen atoms dampening the vibrancy of the red hydrogen alpha atoms, both of which are divided by dark rifts of dusty nebulosity. Eta Carina spans a massive 120x120 arc minutes across the sky and resides approximately 10,000 light years away. Toward the bottom of the image is the open star cluster IC 2602, also known as the Theta Carinae Cluster or Southern Pleiades. The cluster is at a distance of about 479 light-years away from Earth and can be easily seen with the naked eye.
Other rubbish people normally glaze over;
The presented image is a six panel straight RGB composite mosaic comprising of 4.5hrs RGB per panel (9x600s per channel). No luminance data was aquired, though I did create a synthetic lum to better match the Ha data. Talking Ha data, a culmination of 8 hours Ha data was also acquired on specific targets across the scene to provide more depth and detail. The Ha blend was not used extensively, but simply blended in between 30% to 40% opacity. Probably seems a waste to not push it to a higher percentage, but I've been down that complex path before with mosaics and its a real headache to get the right Ha+R blend across the panels. Given time, anything is possible but I simply wanted to get an image out there with the new set up and move on. A base RGB is relatively easy to deal with for mosaic work.
Overall, the data set could have been better. I collected considerably more data than I used, throwing away subs due to focuser problems. These have now been resolved so I expect the acquisition efficiency will again rise to an acceptable level. I do have another data set of a different target that was acquired before the focuser remedial activities so expect to trash it and start again or work with what I've got. I hope to share this soon.
I opted for a 10% overlap between panels which worked out well, though minor rotation was present. The mosaic plan is attached below for reference. With the 16803 chip, its possible to compromise on imaging area real estate if needed given its size. The mosaic plan was quite unique and probably requires a little explanation. The goal was to provide an arch of usual features across the top, IC2944, NGC3576 and NGC3372. To recenter the image, I used IC2602 (Southern Pleiades) as the focal point at the bottom. What appears to be a void to the left of IC2602 contains RCW58. The mosaic spans 10.5 x 7.1 degrees. Took a while to work out the most optimal framing, but I think it works even if a little tight in some areas.
Rusty on the mosaic processing skills so have dropped the ball on fundamental items. The colour matching is not seamless and due to the nature of the data set, I'm not inclined to address it. Just enjoy it for what it is. Usual processing tools were used - CCDStack, Registar and PS CS4. Though I did use DDP in MaximDL for the Ha blends. No major trickery. I think a few single frame images will get me back into the swing of things, but who knows...mosaics open up a world of possibilities providing a unique view time again.
The presented full size image has been reduced by 50% percent and heavily compressed to make it web friendly. Note: it is still 13Mb in size! Still worth the wait to have a swim around. Will leave the full resolution (11,167 x 7403) for prints.
Thanks for looking. Hope you enjoy it. :)
Cheers
Have not produced an image with the "local" gear for well over five months. Feels like all I've done is capture data night after night with no result to show...especially considering the initial intent was to perform a quick test with the new camera. Alas, I got carried away and ended up with a long duration imaging project. When I first joined the IIS community, Glen (Glenc) provided a challenge if I could image an area across from Eta. For the life of me, I can't remember which direction from Eta was requested...so I hope this will suffice given its taken a few years to get this far! Apologies Glen! :)
So without further ado, I pleased to present Environs of the Hibiscus (http://cosmicphotos.com/gallery/image.php?fld_image_id=210&fld_album_id=9).
Warning - large resolutions may take time to load.
Wha?! the Hibiscus?! :screwy: Green thumb eh?
Scene description;
The southern sky in the constellations Crux and Carina is filled with an entourage of impressive deep sky delights. In the image presented above, from left to right is IC2944 the Running Chicken Nebula, NGC3576 at center followed by the large nebula complex of NGC3372 more commonly known as the Eta Carina Nebula. Numerous star clusters also scatter the field. Wide field panoramas such as this, Eta Carina takes on the appearance of a Hibiscus flower. Lush petals produced by blue oxygen atoms dampening the vibrancy of the red hydrogen alpha atoms, both of which are divided by dark rifts of dusty nebulosity. Eta Carina spans a massive 120x120 arc minutes across the sky and resides approximately 10,000 light years away. Toward the bottom of the image is the open star cluster IC 2602, also known as the Theta Carinae Cluster or Southern Pleiades. The cluster is at a distance of about 479 light-years away from Earth and can be easily seen with the naked eye.
Other rubbish people normally glaze over;
The presented image is a six panel straight RGB composite mosaic comprising of 4.5hrs RGB per panel (9x600s per channel). No luminance data was aquired, though I did create a synthetic lum to better match the Ha data. Talking Ha data, a culmination of 8 hours Ha data was also acquired on specific targets across the scene to provide more depth and detail. The Ha blend was not used extensively, but simply blended in between 30% to 40% opacity. Probably seems a waste to not push it to a higher percentage, but I've been down that complex path before with mosaics and its a real headache to get the right Ha+R blend across the panels. Given time, anything is possible but I simply wanted to get an image out there with the new set up and move on. A base RGB is relatively easy to deal with for mosaic work.
Overall, the data set could have been better. I collected considerably more data than I used, throwing away subs due to focuser problems. These have now been resolved so I expect the acquisition efficiency will again rise to an acceptable level. I do have another data set of a different target that was acquired before the focuser remedial activities so expect to trash it and start again or work with what I've got. I hope to share this soon.
I opted for a 10% overlap between panels which worked out well, though minor rotation was present. The mosaic plan is attached below for reference. With the 16803 chip, its possible to compromise on imaging area real estate if needed given its size. The mosaic plan was quite unique and probably requires a little explanation. The goal was to provide an arch of usual features across the top, IC2944, NGC3576 and NGC3372. To recenter the image, I used IC2602 (Southern Pleiades) as the focal point at the bottom. What appears to be a void to the left of IC2602 contains RCW58. The mosaic spans 10.5 x 7.1 degrees. Took a while to work out the most optimal framing, but I think it works even if a little tight in some areas.
Rusty on the mosaic processing skills so have dropped the ball on fundamental items. The colour matching is not seamless and due to the nature of the data set, I'm not inclined to address it. Just enjoy it for what it is. Usual processing tools were used - CCDStack, Registar and PS CS4. Though I did use DDP in MaximDL for the Ha blends. No major trickery. I think a few single frame images will get me back into the swing of things, but who knows...mosaics open up a world of possibilities providing a unique view time again.
The presented full size image has been reduced by 50% percent and heavily compressed to make it web friendly. Note: it is still 13Mb in size! Still worth the wait to have a swim around. Will leave the full resolution (11,167 x 7403) for prints.
Thanks for looking. Hope you enjoy it. :)
Cheers