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View Full Version here: : My first HaRGB- NGC6334, aka "The Cat's Paw"


[1ponders]
09-08-2008, 10:28 AM
This is my first attempt at a HaRGB image.

The Ha was taken last night using an ATik 16IC attached to a WO 72FD, focal reduced to about f/5 or so (9@900sec, 1.25" Astronomic Ha filter). The RGB was from the previous night using a modded 20D, ED80 and WO 0.8 FR (9@300sec @ISO800 ICNR). The Ha and RGB images were processed separately using IP and PS and then registered in Registar and combined using a luminance layering in PS. Image Scale is about 4.7 arcsec/pixel

I'm moderately happy with it for a first shot, but many of the stars came out with grey halos. I'm not sure whether this is from the processing or from the FR I was using with the Atik, most likely the latter I suspect. I also found it a challenge to bring the colour back out after applying the Luminance layer (too pink). I'm waaayy out of practice. I've hardly shot a serious set of images , (apart from Duckadang and I'm still working on those :sad: ) in months. It's nice to be out there again with some good skies.

beren
09-08-2008, 11:54 AM
:thumbsup: Very nice Paul, great to see your getting some time in

Garyh
09-08-2008, 04:48 PM
Nice and deep Paul! Neb looks a little yellow? but lots of Ha detail..
cheers

seeker372011
09-08-2008, 07:59 PM
colour-maybe a hint of the the dreaded salmon pink-but thats a fantastic amount of detail in the neb. May be you should try the Richard Crisp trick of blending a bit of H alpha data into the blue

http://www.narrowbandimaging.com/synthetic_rgb_page.htm


H alpha rules!

IanL
09-08-2008, 10:27 PM
Sweet as Paul

Ian

[1ponders]
10-08-2008, 10:22 AM
Thanks for the link Narayan, I'll give it a go. :thumbsup:

peter_4059
10-08-2008, 10:44 AM
Lots of fine detail in this one Paul. What size chip does the Atik have in it is it 1/2"?

[1ponders]
10-08-2008, 10:53 AM
659x494 pixels @ 7.4 micron Peter = 4.9 x 3.7 mm (6.1 mm diagonal) A bit bigger than a ToUcam chip :P

strongmanmike
10-08-2008, 01:15 PM
Looks quite good Paul, perhaps a little washed out but quite nice indeed.

Mike

AlexN
10-08-2008, 07:04 PM
great image, Paul. How fiddly was it to combine the color data with the Ha?

I love the way Ha makes fainter details 'pop'.. Creates an extremely detailed image!

Can you use Ha filters on a color CCD/DSLR?

Craig.a.c
10-08-2008, 08:16 PM
That is an amazing image. Well done.
What constillation is that nebula in?

[1ponders]
11-08-2008, 01:35 PM
Alex, yes you can but its success will be only moderate at the best. On an unmodded DSLR you would be wasting your time as that wavelength is filtered out anyway by the incamera IR filter. With a modded camera you may have some success (again depending on the filtering) but only 1/4 of the pixels would record any red light. The rest being filtered for blue and green light would remain black. Ha imaging really requires a mono camera.

Craig, The Cat's Paw in near Shaula (the sting in the tail of Scorpius). http://www.ne.jp/asahi/stellar/scenes/seiza/sco.jpg