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View Full Version here: : Lobster Nebula (NGC6357)


dugnsuz
28-06-2009, 03:06 PM
Hi all,
One of these work in progress type posts - poor weather has stopped me obtaining the Ha data I crave for completing this image, so I'm posting what I do have to gauge feedback.

Lobster Nebula (NGC 6357) in Scorpius.

Canon 40D (modded)
Canon 300mm f4L IS lens + 1.4x Extender (FL=420mm)
Hutech IDAS LPS2 Filter.
HEQ5 Pro mount.
18x600sec (3Hrs), iso1600.
ICNR on, no flats.
Autoguided with PHD.

Stacked + Processed using ImagesPlus and Photoshop CS4.

High Res...
http://s327.photobucket.com/albums/k461/doug-robertson/?action=view&current=22b.jpg


Got some dodgy star issues on this pic - I attach the 72mm Hutech filter to the lens with a 72-77mm stepper ring, and I think this is making them look a bit asymmetrical and shifting the focus point a bit too resulting in the colour aberrations seen.:(

Hope to get equivalent amount of Ha soon to complete this one!

Cheers for looking...
Doug

TrevorW
28-06-2009, 03:20 PM
:thumbsup: Nice one Dougie with this and the prawn we are having as seafood platter of astronomical delights

I can see what you mean by the slightly odd star shape

Tamtarn
28-06-2009, 04:20 PM
The nebula detail looks good Doug but the levels look a bit clipped on our two monitors.

Hope you get the extra data you need to finish it. Should be a beauty :thumbsup:

jase
28-06-2009, 04:31 PM
A good start to the project Doug. The RGB data looks rather rich - a good thing when attempting to blend it with some contrasty Ha data to minimise washout. You maybe able to correct the star shapes with the Ha data. See how you get on with an LLRGB blend. Before Ha data for the second time, make adjustments to the RGB stars. Worth a shot. Look forward to seeing the final result.

dugnsuz
28-06-2009, 04:59 PM
It does, but PS tells me otherwise:shrug:
Doug

jase
28-06-2009, 05:09 PM
If you hold down the 'Alt' key and click/move the black point slider, you'll see where in the image clipping is occurred. It could be another key on a Mac. The image gives the perception that clipping has occurred, but in actual fact it hasn't. Certainly is tight with very little white space between the data and black point, but no data lost - a good thing.

Hagar
28-06-2009, 06:17 PM
Looks good Doug. I hope you get your Ha data. It looks interesting. The high saturation level should allow for a bit of washout when the Ha Lum layer is added. Star shapes, well if you lived here you would get use to these problems with it being very hard to get the FWHM down below 6 except on those very rare occasions and usually I am at work for these events.
Interested to see the final cut.

Alchemy
29-06-2009, 06:30 AM
as its a work in progress, generally a little latitude is allowed,

( but now that youre a malin award winner ) :D

on the final image i would be looking for subtle color in the stars, as this isnt overly evident on the IIS 200kb version.

will look out for the finished product.


well done with your award BTW


cheers clive.

dugnsuz
29-06-2009, 09:11 AM
Cheers Clive - yes, it really is tough at the top:P

Craig_L
29-06-2009, 11:11 AM
Nice one Doug. 3 hours on the RGB! Leaves you a few nights work on the Ha but should look good.

dugnsuz
29-06-2009, 11:26 AM
Thankyou sir!
Managed to get 6x10mins and some shorter subs for masks last night, but that looks like it might be it for a while weather-wise :thumbsup:

toryglen-boy
29-06-2009, 11:28 AM
its a nice image Doug, hopefully one day i can produce something like this.

;)