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View Full Version here: : Deep NGC6334 and NGC6357 in 3nm NII


avandonk
28-06-2012, 10:26 AM
This is 20x8 minutes of exposures in 3nm NII 9MB

http://d1355990.i49.quadrahosting.com.au/2012_06/NGC6334&6357.jpg

It is also 1.5 times native pixel size.

The small amout of flex is due to the wood frame. It will go away with the aluminium cradle.


Bert

gregbradley
28-06-2012, 03:56 PM
Nice shot Bert.

I'd suggest trying 2x2 binning to overcome the bckground noise and increase the signal to noise ratio. Its one way to increase SNR whilst you work on the flex so you can get longer exposures. 3nm was always going to need 15-30 min exposures to build enough signal.

I find 2x2 works well with my CDK17. You've got plenty of res there and you don't drop that much resolution anyway.

Greg.

avandonk
29-06-2012, 10:43 AM
Greg I have processed the data with tone mapping which can accentuate the dim stuff all the way down to the noise without blowing out the bright stuff.

This is a stretched version without tone mapping 6MB

http://d1355990.i49.quadrahosting.com.au/2012_06/NGC6334&6357N.jpg


With tone mapping 9MB

http://d1355990.i49.quadrahosting.com.au/2012_06/NGC6334&6357.jpg


Animated gif to show the effect of tone mapping 5MB

http://d1355990.i49.quadrahosting.com.au/2012_06/6334.gif


Bert

gregbradley
29-06-2012, 05:25 PM
I personally like the stretched version better as its got a nice smooth background.

You are getting more contrast with the tone mapping but it comes at a cost of the grainy background.

Its looking good Bert.

Greg.

Fabiomax
30-06-2012, 06:30 PM
Congratulations, what really impresses me in this image is the contrast that the nebulae. Very very nice,
Cheers,
Fabiomax