NGC346 in the Small Magellanic Cloud repro'd

[gregbradley]

Whilst perhaps not that photogenic this object is not imaged very often.

There is more Ha nebula in that region than is generally shown in Small Magellanic Cloud images.

CDK17, Proline 16803, Paramount ME.

The Ha image turned out the best. As you can see there is a lot more Ha nebula in that area
of the Small Magellanic Cloud than normally shown in images. NGC346 is the largest neb in that
area lower in the image.

Colour:
http://www.pbase.com/image/137931271 regular

http://www.pbase.com/gregbradley/image/137931271/original large


Here is a more muted colour version that retains the delicate O111 bluish tinge in the centre
than the other colour version which is heavy in Ha:

http://upload.pbase.com/gregbradley/image/137935383/large

Ha:
http://www.pbase.com/gregbradley/image/137931641/large regular

http://www.pbase.com/gregbradley/image/137931641/original large

Greg.

[h0ughy]

looks like a playgroup painting - splotches and dots everywhere.

looks an interesting area but it does seem very soft - almost not quite focused

[gregbradley]

Seeing was rather poor and I think that is what you are seeing there.
The CDK focus tends to be the same every night pretty much. It shifts a bit but if the temp is similar I find it hasn't really changed from the night before.

Greg.

[h0ughy]

yep you are quite right - as i will find out with my 14 meade, would it be a case of the larger the scopes get the more picky or sensitive to seeing?

it still looks like what my daughter would to bring home ;):)

[gregbradley]

Hehe.:)

Most definitely. The effects of seeing are always there no matter what size scope. But the wider the field the less you see the blur from the seeing. Just like tracking defects are less visible in wider field images. Everything is on display in long focal length imaging. Generally though the CDK17 isn't as sensitive to seeing with the reducer on. But to the south I don't think is my best view here.

[leinad]

Thats a nice target to image Greg. Seems to have a bit of everything. The processing look a little 'flat' ?

Can I ask if you stacked this as HaRGB before PP, or RGB then Ha Luminance in processing?

Took me a while to look at it on/off to see the details pop out. Looks like some heavy noise reduction has affected the non-selective areas and killed the object a bit.

[atalas]

Composition is wonderful Greg!I like It....obviously more data will be worth the effort.

[desler]

A hard object to get a handle on. The smaller image works best for me, the larger file seems to be a bit soft. Overall though a very interesting area with obviously lots going on.

Darren

[gregbradley]

I didn't do any noise reduction. It is quite a small object and seeing was not the best. Not sure what PP means (post processing?). I did not use Ha as luminance very much as it kills color. I used a tad I think but hardly any.
Ha is blended in after RGB combine and processing as layers. This is my usual routine. That way I have maximum control rather than doing a HaRGB combine and then processing. Both ways probably work and I know some do it that way by adding Ha and Lum together and Red and Ha together. I prefer to add Ha as layers as I have total control over the effect of the Ha.

I don't think it has a lot of detail really. The Ha by itself was probably the most interesting subexposure with the most amount of detail.



Thanks Louie.

Its not the most impressive astroimage but I thought it was worth posting as it is unusual.

[gregbradley]

Yes it did turn out soft. I assume that was seeing. Imaging to the south is not my best spot from my observatory I have noticed. Probably it depends on the night.

Greg.

[gregbradley]

I realised why it was soft, there is no luminance layer.

So I reprocessed everything and did some deconvolution on each of the RGB subs to tighten them up (2x2 binned).

It looks a lot sharper now and more vibrant.

The Ha only is also quite interesting.

Colour:

http://www.pbase.com/image/137931271 regular

http://www.pbase.com/gregbradley/image/137931271/original large

Ha:

http://www.pbase.com/gregbradley/image/137931641/large regular

http://www.pbase.com/gregbradley/image/137931641/original large

Greg.

[strongmanmike]

A nice close up of an interesting bit of the SMC Greg, the pinky red looks good :thumbsup:

Cheers

Mike

[gregbradley]

Thanks Mike. It may be worth a look at it again in case you caught it whilst I was updating it. There's more in that area than you normally see as it is quite a small nebula.

Greg.

[strongmanmike]

Aaah now I can't tell...but I think the version I saw previously was better..? This looks flatter :shrug: ...not much in it so don't fret :)

Mike

[Stevec35]

Hi Greg

Nice detailed shot of this very interesting SMC region. I'm afraid I'm not convinced about the colour though. There is a lot of OIII in this nebula and I think the influence of the Ha is exaggerated in your image. Here's my own version of it:

http://members.pcug.org.au/~stevec/ngc346_STL11K_RC_HaRGB.jpg

I'm quite prepared to roll over if I'm wrong <g>.

Steve

[gregbradley]

The RGB is definitely bluish. If I add some O111 it would bring that up more

Greg.

[desler]

I rekon the repro's are great. The Ha data is spot on.

Would better seeing / more subs bring out more detail in the clouds. They really are something to look at.

Darren

[gregbradley]

Thanks Darren. Better seeing and more exposure would help for sure

Here is another version that is more muted colourwise retaining the more delicate bluish O111 part in the centre as Steve pointed out.

http://upload.pbase.com/gregbradley/image/137935383/large

Greg.

[RickS]

Greg,

How long were the Ha exposures? I did an hour and a half of Ha on NGC 346 myself a couple of nights ago. It was my first attempt at Ha and still quite noisy. I probably needed a couple more hours at least...

Thanks,
Rick.

[gregbradley]

10 minutes I think.

Greg.

[RickS]

Thanks. How much total exposure time?

[gregbradley]

3 x 15minutes at 2x2 binning F4.45 17 inches aperture, 61% QE chip.

Greg.

[RickS]

Thanks, Greg. Nice, fast scope!

[Ross G]

Hi Greg,

Great photo of an unusual object for me.

I like the colours and the detail.

Thanks.

Ross.

[Stevec35]

Hi Greg

Looks better now although still a shade too red for my taste. You don't need to add O III. I just had 75 minutes each of R,G and B in my version.

Cheers

Steve