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yock1960
Pooh-Bah
Reged: 06/22/08
Posts: 1127
Loc: SW Ohio, USA
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Here is M33 after 6+ hours (5 & 6 minute subs) under LP skies with my OSC DSI-III.
There is still a bit of a gradient that needs dealt with and the stars aren't quite round, but I'm not unhappy with it.
What I am unhappy with is the fact that I had to (I twisted my own arm) do a layer mask and adjust color balance to get the 2 big HII regions to look reddish! I'm learning that this camera has a very different red response versus the CMYG DSI-II, but I would have thought that after 6 hours, I would have gotten some red! I'm starting to wonder if it's something in how I'm processing! I mean, I don't seem to have a problem with red/yellow stars. But in the first month of using this camera, emission type stuff may as well be invisible!
What can I do?
Steve
M33
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LXD75 GEM
Orion Starblast 4.5" Imaging Reflector
William Optics Zenithstar 66 SD APO
Meade DSI II OSC
Meade DSI III OSC
Orion Starshoot Autoguider
Televue Powermate 2.5x
Discovery 6" Dobsonian
Nikon Action Extreme 10x50's
Gallery (older stuff)
Picasa Gallery (newer)
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budguinn
Post Laureate
Reged: 11/24/04
Posts: 4631
Loc: Gold Beach, Or
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Hi Steve,
Not sure why the camera isn't giving more red, but you have a pretty nice image.
Until you get the guiding under control you can always remove the elongation in PS.
Are you using flats, or what are you using to remove the gradients....this might be robbing some of the reds.
--------------------
Warmest regards,
bud guinn
http://www.budguinn.com
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yock1960
Pooh-Bah
Reged: 06/22/08
Posts: 1127
Loc: SW Ohio, USA
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Thanks Bud!
I have a lightbox that I use for flats, I also use PI's DBE. I suppose I could try not using the flats, just to see if that's part of it. Of course, I obviuosly misspoke a bit. I do get reds, if they are bright enough, like in M42.
As far as the elongation, I have a star rounder plugin for PS. Also, PI does a pretty decent job using it's MorphologicalTransform, but they both have undesired effects on the rest of the image. Even with masking, it's a matter of how much effort to go back to fix that. It can be a chore with alot of stars.
Steve
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LXD75 GEM
Orion Starblast 4.5" Imaging Reflector
William Optics Zenithstar 66 SD APO
Meade DSI II OSC
Meade DSI III OSC
Orion Starshoot Autoguider
Televue Powermate 2.5x
Discovery 6" Dobsonian
Nikon Action Extreme 10x50's
Gallery (older stuff)
Picasa Gallery (newer)
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David Pavlich
Postmaster
Reged: 05/18/05
Posts: 9712
Loc: Mandeville, LA USA 30.22 X 90....
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Hey Steve...have you ever looked at the individual histograms for R, G and B and compare them? I'm a real neophyte when it comes to processing, but maybe you could try setting the black points/white points in the individual colors as your first processing step to perhaps even the score between the 3 colors.
If I'm all wet here, one of you veteran processors stop Steve before I mess him up. 
David
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Proud Member; PAS NOLA,
"If we knew what we were doing, it wouldn't be called research..."
A. Einstein
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bill w
Postmaster
Reged: 03/26/05
Posts: 7182
Loc: southern california
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getting a good amount of signal there
i'd suggest G2 color balancing
http://starizona.com/acb/ccd/advtheorycolor.aspx
it sounds a bit complex
but you can get away with doing it just once to characterize your system
--------------------
-bill w
nexstar 8 GPS
canon 300D, Toucam Pro II
SXV-H9C, H9, SX Exview autoguider, SX-AO
FS 102 (OLV), FS60 CSV, 8" LX200R, G 11
http://astro.whwiii.net/
image processing monitor calibrated to just differentiate darkest boxes:
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yock1960
Pooh-Bah
Reged: 06/22/08
Posts: 1127
Loc: SW Ohio, USA
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Quote:
getting a good amount of signal there
i'd suggest G2 color balancing
http://starizona.com/acb/ccd/advtheorycolor.aspx
it sounds a bit complex
but you can get away with doing it just once to characterize your system
OK, I got a chance to do this finally this morning. I forgot to defocus, hopefully I can work around that. Anyway, since I'm not shooting with filters, I'm thinking that what I would do is to figure out the ratios and then use them to customize the debayering. Nebulosity allows you to override the defaults and there are x&y offsets and a 3x3 matrix that is something like this:
Red 1.00,0.00,0.00
Green 0.00,1.00,0.00
Blue 0.00,0.00,1.00
Can I just change the three 1.00 values to the calculated values? Or is there more to it?
Steve
--------------------
LXD75 GEM
Orion Starblast 4.5" Imaging Reflector
William Optics Zenithstar 66 SD APO
Meade DSI II OSC
Meade DSI III OSC
Orion Starshoot Autoguider
Televue Powermate 2.5x
Discovery 6" Dobsonian
Nikon Action Extreme 10x50's
Gallery (older stuff)
Picasa Gallery (newer)
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turbo399
sage
Reged: 12/21/07
Posts: 250
Loc: Michigan
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Hi Steve
Very nice image, I shoot with a OSC camera and it's not as sensitive but I finished up doing over 12 hours on M33 to bring out the red http://www.flickr.com/photos/terryhancock/4033682523/
So perhaps more subs is what you need
Terry
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TMB 130SS F7 Refractor
TMB 80SS F6.3 Refractor
Celestron CGE PRO Mount
Canon 5D Mark II modified
Canon 450D modified
Orion Autoguider
www.flickr.com/photos/terryhancock/
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yock1960
Pooh-Bah
Reged: 06/22/08
Posts: 1127
Loc: SW Ohio, USA
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Nice image Terry! 12 hours huh? I guess I better get crackin'. Once the skies clear again anyway.
I did discover one thing. I'm not sure it makes a difference yet, but in Nebulosity there is an advanced settings panel, where you can set amp off,fast reads, binning if available and a few other odds & ends. There is also a setting called 'gain boost', which had been unselected. I hardly ever went into this panel when using my DSI-II, but in getting an old laptop ready to become my imaging laptop, I had my DSI-II attached and noticed that the default is to have 'gain boost' selected. So, all of my imaging using Nebulosity and the DSI-II had been with the gain boosted. As I said, I'm not sure it really makes much difference, but I'll find out.....when the weather clears.
Just trying to squeeze every last photon for all it's worth!
Steve
--------------------
LXD75 GEM
Orion Starblast 4.5" Imaging Reflector
William Optics Zenithstar 66 SD APO
Meade DSI II OSC
Meade DSI III OSC
Orion Starshoot Autoguider
Televue Powermate 2.5x
Discovery 6" Dobsonian
Nikon Action Extreme 10x50's
Gallery (older stuff)
Picasa Gallery (newer)
|
bill w
Postmaster
Reged: 03/26/05
Posts: 7182
Loc: southern california
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Quote:
Quote:
getting a good amount of signal there
i'd suggest G2 color balancing
http://starizona.com/acb/ccd/advtheorycolor.aspx
it sounds a bit complex
but you can get away with doing it just once to characterize your system
OK, I got a chance to do this finally this morning. I forgot to defocus, hopefully I can work around that. Anyway, since I'm not shooting with filters, I'm thinking that what I would do is to figure out the ratios and then use them to customize the debayering. Nebulosity allows you to override the defaults and there are x&y offsets and a 3x3 matrix that is something like this:
Red 1.00,0.00,0.00
Green 0.00,1.00,0.00
Blue 0.00,0.00,1.00
Can I just change the three 1.00 values to the calculated values? Or is there more to it?
Steve
afraid i'm not familiar with nebulosity
but it sounds like you're on the right track.
*as long as you're in the linear range of your camera*, defocussing isn't critical.
one other thing you might try is a gaussian blur of radius 1
on the g2v star image to smooth out the variation a bit
--------------------
-bill w
nexstar 8 GPS
canon 300D, Toucam Pro II
SXV-H9C, H9, SX Exview autoguider, SX-AO
FS 102 (OLV), FS60 CSV, 8" LX200R, G 11
http://astro.whwiii.net/
image processing monitor calibrated to just differentiate darkest boxes:
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