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View Full Version here: : Rosette Nebula NGC2237 in Ha


troypiggo
27-01-2012, 10:29 PM
This is 10x4min subs of Ha only taken with the QSI 583ws on the humble ED80 from heavily light-polluted home. Tried to get some colour data to add to it but the clouds have had other ideas, so grayscale it is for now.

DavidTrap
27-01-2012, 10:34 PM
Very nice Troy.

BTW, when did you see some sky?

Have you tried any longer subs with your Ha filter? I'm shooting 15 mins.

DT

RobF
27-01-2012, 10:50 PM
Nice Troy. It sure has been hard to see any stars for last few weeks. :sadeyes:

Hope you get more time to finish it in the near future.

troypiggo
27-01-2012, 11:33 PM
Thanks mate. There was a few hours last Friday night. Snuck a bit in then.

I could push longer subs with the Ha, and probably will next time. Heaps of LP at Auchenflower :(



Thanks Rob. Me too. :). It is a bit noisy in the background I know. Needs more data.

DavidTrap
28-01-2012, 08:14 AM
I thought NB imaging was "immune" to LP?

DT

midnight
28-01-2012, 11:24 AM
But it is certainly coming along nicely. Good luck with getting more data!

Darrin...

multiweb
28-01-2012, 03:29 PM
Great shot Troy. Go the ED80. :thumbsup::thumbsup::thumbsup:

ozstronomer
28-01-2012, 09:39 PM
Looking good mate, well done on a great shot :thumbsup:

Now to get some clear skies for the extra data

peter_4059
28-01-2012, 09:49 PM
Great shot Troy. I'm impressed - the ED80 worked well with 4min Ha subs. Must give that a try.

troypiggo
28-01-2012, 10:47 PM
My understanding is that it certainly helps cut through the LP, but that doesn't make it immune. I guess there is still some transmission at all wavelengths that leaks through? Someone more knowledgeable than I could correct me, please.

That being said, I would like to do some more testing at longer subs to see what I can push it out to.









Thanks guys. Was good to get the ED80 out and just grab some data after all the time-consuming tinkering I've been doing with the 10".

Ross G
29-01-2012, 01:57 PM
Good looking photo Troy.

I really like the monochrome look.

Ross.

wysiwyg
29-01-2012, 02:33 PM
Troy,

Nice image, but its worth going deeper on this one.
If you can manage it, go 10min or even 15min subs, you will see a remarkable difference. In darker skies preferably :)

Cheers
Mark

gregbradley
29-01-2012, 03:33 PM
A really nice image Troy. The only comment is you have a gradient going from bottom (bright backround) to top (dark).

If you correct the gradient (Gradient Xterminator or Adam Block tutorial methods using apply image function in Photoshop) you will get more control over the image and can achieve better contrast etc.

One of the most vital processing techniques imaging in light polluted areas even if narrowband is gradient processing. So it pays to study up on the various methods and use them.

I think the best 2 are Gradient Xterminator (often all that is needed) or Adam Block's tutorial using Photoshop and the apply image function subtracting out a copy image which has been blurred and smoothed heavily so as to only leave the complex gradients.

Pix Insight also has a dynamic background tool which is quite good but perhaps more hands on than the above.

Greg.

troypiggo
29-01-2012, 11:34 PM
Thanks again, guys.

Greg - thanks for the constructive critique there. Will look into the gradients. Haven't had much luck to date with PI's background removal, though that's inexperience more than the capability of the software. Will play with some tutorials on it.

troypiggo
30-01-2012, 05:59 PM
I did have a play with the dynamic background extraction in PixInsight, and it did improve the gradient. Thanks again for the tip, Greg.