Ngc4945

[rat156]

Hi All,

Here's my attempt at this very nice galaxy.

Taken with my 10" Meade RCX at prime focus, with an SBig ST-10XME, AO8 with a MOAG and remote guide head. Guided on a bright star @ about 11Hz.

LRGB image 165, 30, 30, 30 minutes.

Cheers
Stuart

[renormalised]

Nice shot!!. Few little background galaxies in there as well.

[desler]

Very nice Stuart.

Lots of work in that!

Darren

[Hagar]

Nice shot of this dim galaxy Stuart. I do notice some of your stars seem to have little tails. Is this a result of guiding or is it a bloom?
Also I wondered about the blue flash on the right hand side of the image.

The dust lanes and resolution of the galaxy is great.

[Matty P]

Excellent image Stuart. The detail in the galaxy is resolved very nicely.

Very nice setup as well.

Great image, well done. :thumbsup:

[rat156]

Hi Hagar,

If they're vertical in the image from the bright stars it's diffraction from the lenses on the front of the ME chip. Other than that I actually can't see any.

The blue flash is a bright star off screen, can't do much about that.

Cheers
Stuart

[multiweb]

It's beautiful. Great colors. I really like the processing on that one. :thumbsup:

[Lester]

Very nice image, resolving much detail within the galaxy.

Good one Stuart.

[iceman]

Really nice Stuart, heaps of image scale and detail.

I feel it should be framed a bit more in the centre, that's all though :)

[gregbradley]

That turned out pretty nicely.

Greg

[gregbradley]

Hi Stuart,

Try lassoing the blue area and then feather it 25 pixels then use curves/blue channel and try to pull it down.

Then you can use the sponge tool set to desaturate 5% and rub on the affected area to reduce it even more.

Greg.

[Bassnut]

Excellent detail and star colour there Stuart, and nice to see you got a guide star bright enough to go 11hz.

How do you find the MOAG?, solid enough to hold all the gear without flex?. It seems to be the best one available. Is it smooth to rotate finding a star?.

[jase]

A very tidy image Stuart. Excellent details and great colour. The image doesn't have a heavily processed feel which is pleasing. Composition is a little odd being offset, but I suspect this may have been the result of finding an ideal guide star for the AO kit - trade off.

You can do as Greg mentions to remove the blue flare from the background, but in my experience you'll find the method is tedious given you only want to manipulate the sky background and not impact the stars in the region. Its also complex when using curves to drop a hue and not cause imbalance to the surrounding feathered area.

Here is my preferred method to detailing with such background colour flares from pesky stars off the edge of the frame. It can also be used to repair other issues. For example, in the recent Rho image I posted, the star halo reflections were are bright green. I simply used this technique to address them. Its a little more involved, but the result is very accurate.


Click on the lasso tool and set the feathering to approx 20 pixels
Using the lasso tool, select an area that is of same size and is relatively close to the colour flare area you wish to remove. The purpose of this exercise is to match the background hue of the surrounding area so the proximity to the area you're trying to fix is fairly important. At this point, don't worry if the selected area contains stars.
Copy and paste the lasso area so you now have a new layer that contains the small patch of the sky in which you've just copied.
Hold down the control key and move the mouse to shift the small patch over the colour flare area you wish to remove.
Now go to the Filters | Noise | Median
Increase the radius until you see no more stars in the small patch of sky that you've copied. If you don't like the median tool, dust and scratches, or the minimum filters can do a similar job. Median I've found works well in general.
With the patch layer selected, change its blend mode from normal to colour
You'll now notice that your colour flare has disappeared i.e. has been blending into the surrounding background hues. If it hasn't you may need to increase your selection size or reduce the feather.

...but don't stop there...look what you've done to the stars in the area that's been repaired...they've inherited the same background tone you copied. Easily fixed...


Select the original layer and use the colour range tool to highlight the stars. Alter the fuzziness slider until you get a good match.
Expand the selection by 2 or 3 pixels (or to your taste)
Feather by 2 pixels (or to your taste)
Then select the patch layer (important, make sure its selected!!)
Hit the delete key
POW! You've now brought the star colours back in the repaired area...as you've deleted the selections from the patch layer so the colours come back through from the original layer.
If you find that the colour range tool selection wasn't ideal, you can always use the eraser tool to do a similar task, but I would recommend going back a few steps until you get the right selection i.e. manipulate fuzziness.

Give it a try! Should probably have posted this in the photoshop tips section. May put a cross reference to it somehow.

Cheers

[Paul Haese]

Lovely image Stuart. Makes mine look a bit ordinary. However, it gives me some idea of what I can expect with the QSI when I get it. Thanks for posting.

[rat156]

Hi Paul,

No I don't think it makes your ordinary at all. I've been doing this for a while now, you've only just started and have a new scope etc. to deal with. The el-cheapo RC is showing real promise IMHO, the 10" or maybe 12", if they get around to making them, would be my new choice for a DS imaging scope.

The main differences between yours and mine are image scale, which makes a nice change for me as it's usually your planetary images that have that huge image scale I strive for, but can't quite achieve.

The AO unit helps, mainly because I'm still using the Meade fork mount. The luminance subs were 15minutes, which really helped to bring out the outer detail in the galaxy. So to the naysayers out there that reckon you can't image with a fork mount, it can be done. You just require the right camera and an AO unit, the OAG stuff isn't necessary until you want to do narrowband stuff, then it helps. A $20k mount is no longer necessary for long exposures, which is great for those of us that wouldn't mind going out to dark skies every now and again, I couldn't imagine taking a paramount to a star party!

Do you know if the QSI mob are planning an AO unit for their cams? With the integral OAG it seems a logical step.

Cheers
Stuart

[Paul Haese]

Yeah true about the time frame Stuart. Although I have been dabbling in DSO off and on for over 25 years. Was good at film but as you know digital is a whlle new ball game. I always have very high expectations of myself, much more than anyone else in regard to my imaging.

I am not sure what QSI are planning with regard to an AO unit if they are planning anything at all. I doubt they have anything in the planning. I like the idea of the integrated OAG, it will certainly get rid of flexure.

[rat156]

Yeah, it's a way of competing with SBig without infringing on their patent. I like the modular approach of the QSI, do you have to get everything at once, or can you add modules later?

We should probably start a new thread in the cameras forum do discuss this though, not really related to my image anymore.

Cheers
Stuart

[Jeffkop]

Great image Stuart ... actually the best Ive seen of this object, and way better than my attempt at it last winter. The scope and camera combination are working well.

[AlexN]

Stuart - Firstly, Fantastic image! looks like the setup is preforming brilliantly!

Fred and I had a quick talk yesterday about the advantages of the MOAG, remote guide head and AO8.. This image shows the advantage clearly... the detail is sensational and the guiding looks absolutely unreal.. I love it and can't wait to save some money for the remote guide gear, MOAG and AO8.. :)

Good going!
Alex.

[Paul Haese]

Stuart, you can add the parts as you want, I just got everything at once.

[TrevorW]

Top image gets my vote

[gregbradley]

Nice tip Jase.

I'll drill that and start using it myself.

Cheers,

Greg.

[Alchemy]

very impressive detail in the galaxy,

when i go to save the image a little warning pops up about the copyright ( as always) i only redistributed it to my hard drive :whistle:, a keeper for my collection.

clive

[rat156]

I've added the reprocessed image according to Jase's instructions, certainly has gotten rid of the blueness to the flare. As It's still there in the Luminance channel the streaks are still there, but they are there on the other side of the galaxy as well...

Cheers
Stuart

[jase]

I've come back to check your work out again a few times. Really like the detail you've obtained. The recent adjustment has certain reduced the distraction. I don't think I'd probably worry about the luminance flare... I guess this is a case of how far you want to take it. With the flare colour gone, you could follow up on the luminance with the following. Its similar to what I advised previously to bring back the star colours (just leave the layers as a normal blend this time).


Duplicate the luminance layer and select the new layer
Go to the Filters | Noise | Median
Increase the radius until you see no more flare in the luminance. Its ok to blur it relatively hard as you can dial back the adjustment later using the opacity settings or a mask. The goal should be to get rid of it so do what it takes to get that far.
Select the original luminance layer again and use the colour range tool to highlight the stars including the galaxy. The stars are more important at this stage so focus on these. Alter the fuzziness slider until you get a good match. Make sure you get those faint ones (a high fuzziness setting).
Expand the selection by 2 or 3 pixels (or to your taste)
Feather by 2 pixels (or to your taste)
Check the galaxy selection and adjust Get the lasso tool out (shortcut L) (feather by 20 pixels or so) and add to the current selection (hold down the shift key to add to selection). Lasso the galaxy so you've got the out reaching arms highlighted.
Recheck the selections. If you find that some of the flare is also selected, subtract it from the selection using the Alt key with the lasso tool.
Then select the duplicated layer that you've performed a median filter on (important, make sure its selected!!)
Hit the delete key
DONE!
The galaxy and stars are brought through the original luminance layer, while the background in which has had median filter applied is taken from the layer above.

You'll probably find that the background will now look too smooth and noise free. While in some cases this is ok, but you want to avoid the plastic feel, a bit of noise is good. You can dial back the opacity a little OR, what I normally like to do is create a hide all layer mask on the duplicated layer. Then you can use a paint brush to paint the mask to reveal the median filtered luminance background on the affected areas. You can't impact the stars as they've already been removed from the layer. Just dial back the brush opacity and flow (20/20 works well for both settings), but its a matter of preference.

You can do a similar task using an inverse mask, however you'll find that the mask itself may also contain the flare in which you're trying to remove so you'd need to modify it before hand. Of course, theres more than one way to do the same thing in PS. Its just a matter of finding something that works well for you. Hope it helps.

Cheers