View Full Version here: : M42 with 14.5" SDM
mbaddah
31-01-2013, 04:21 PM
Hi,
Thought i'd try a shot at imaging M42 with my SDM from my severely light polluted backyard here in Sydney. I was able to capture approaximately 10minutes worth of data before the clouds rolled in unfortunately.
Equipment used:
14.5" f4.8 SDM (shorter truss poles to bring dslr to focus)
Canon 5D Mk II
Astronomik UHC filter
Shots were limited to 30seconds (due to field rotation and tracking issues) at ISO range from 1600-6400. Stacked in DSS + PS6. My processing skills suck and I don't know how to fix the colour balance caused by the filter.
I'd appreciate any feedback on how to improve this image. Thanks guys.
what good work!
capture some shorter exposureds as well (maybe 10sec at a lower ISO) to get the trapezium and then try overlaying that area of your image so the cores isn't as blown out.
you are well on your way there though, well done
niko
Likewise ... at that focal length it might be best to use ISO800 and 3 to 5 minute subs. Then be careful not to over-brighten the core when "stretching" the image in Photoshop using Curves. Also, when fixing your colour balance in PS, best to do before repeated cycles of using Levels and Curves (to help avoid clipping data).
Hope this makes sense.
Jeff
mbaddah
01-02-2013, 12:07 AM
Thanks guys for the tips.
Jeff I'm not sure I can get 3min subs with a servo cat?
Octane
01-02-2013, 12:29 AM
Mohammed,
That is very, very impressive for your first foray into imaging. Such awesome aperture to capture it with, too!
H
mbaddah
01-02-2013, 06:24 AM
Thanks Humayan:thumbsup:
David Fitz-Henr
01-02-2013, 10:06 AM
That's a great first attempt Mohammed; some nice details in there! Are you referring to the red gradient (brightening to the right)? There are manual methods to fix this in PS, etc, but I'd suggest that you buy GradientXTerminator (or similar) which are specialised s/w tools designed to correct these issues and are not very expensive.
mbaddah
03-02-2013, 06:08 AM
Hi David,
Thanks for the kind words. I was referring to the overall greenish tint look in comparison to everybody else's blue/purple image of M42. I'll look into GradientXTerminator.
Thanks:thumbsup:
Octane
03-02-2013, 09:20 PM
Oh, the green tint is due to the oxygen emission from this nebula. The red/blue/purple comes from cameras that have had the IV/UR filter replaced with a broad spectrum filter that allows the hydrogen alpha line to pass through to the sensor. That's where the reds come from. :)
H
Ross G
06-02-2013, 10:57 PM
Nice capture Mohammed.
Ross.
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