My very humble Sculptor NGC 253.

[alpal]

This galaxy was hard to process due to a very noisy picture.
I suppose that's all you get from a light polluted suburb in Melbourne?

72 minutes of LRGB data in 3 minute subframes with a QHY9 on an 8" Newt.
Larger version here:
http://www.flickr.com/photos/24719437@N03/8104531043/sizes/h/in/photostream/

[Larryp]

That's a nice image:thumbsup:

[tilbrook@rbe.ne]

Not bad!

I take my hat off to you, damn difficult from the burbs.

Cheers,

Justin.

[TrevorW]

Nice one

[alpal]

Thanks guys - it was still nice to get a shot of the Silver Coin.
It certainly came up better than with my DSLR where I had more
time from the same location - also on my flickr page.

Sorry Trevor for stealing your title. :)

[Ross G]

Hi Allan,

What a great capture from the suburbs.

Looks fantatstic.

Ross.

[atalas]

A great effort from your location Al.

[multiweb]

Superb capture. Details are impressive. From light polluted suburbs really? Unreal. :thumbsup:

[alpal]

Thanks Marc, Louie & Ross,
There is actually more detail in the pic than I thought -
it's just a bit smudged from not enough data.
I compared it with some of the top images that other's have
got recently on Ice in Space & I can see where some detail
was trying to get through.

Some more info for those who may be interested:
I took many flats for each of LRGB.
I did that the next day & I tried to be careful to make sure the camera didn't move from it's previous position.
Some dust doughnuts still came through anyway -
I don't know why?
I also took many dark frames at the correct temperature which was - 31.4 degrees C.
I have since learned that I had the sensor too cold
& there is a risk of cracking it so I will go
down to only -20 degrees C in future.

I don't know what caused the blooms or trails from the brighter stars.
I used only a gain of 5% & an offset of 101.
When I sampled the bright stars with the eyedropper in curves using Photoshop
none of the stars reached the top of the scale.

The image does need more time.
Unfortunately the clouds rolled in after only 72 minutes & I had to pack up.

I wonder if I should have used my Astronomic CLS-CCD anti light pollution filter?
I haven't tried it with my new QHY9 & LRGB.
There is however a gap between Red & Green in my LRGB filters which knocks out sodium lamps.

Also for processing this noisy image:
I did 2 sets of stacks: (actually 4 of each making 8 )
(1) for the background with everything set to median
(2) the other for the brighter galaxy with everything set to Kappa sigma clipping.

I then combined the 2 images in layers with Photoshop.
That made a smoother background & sharper details in the brighter galaxy than just one stacking method.
That was a trick I learned from my DSLR days where getting rid of noise was essential.
I also used 40 iterations of iterative sharpening on
the brighter areas of the galaxy using Fitswork4
& blended it in from another layer in PS.

Any solutions to my unsolved questions would be appreciated.
There is still a large learning curve for me but I'm having fun.

cheers
Allan

[David Fitz-Henr]

Hello Allan, great details there! The main commment would be that there appears to be some colour gradients (probably due to light pollution?) - if you could clean these up (I use GradientXTerminator) it should improve the extended image a fair bit. Did you take/process any flat frames? That should fix the dust doughnuts.

[alpal]

Thanks for the kind words.
I did take flats -



I'll leave the gradients alone and move on to my next adventure.
I am actually set up ready to go for a dark site -
it's just the Cloudy skies that are stopping me.