Ngc 5128 repro added

[Shiraz (Ray)]

Originally Posted by strongmanmike

Ah ok, wavelet sharpening seems to have a similar affect to decon on the appearence of the detail, ie it tends to reduce everything to point sources and gives the detail a uniform dotty appearance, this does tend to impart a high res "look" but to me this is not natural (or even real) and stands out very easily, even if one is careful and light handed. The good thing is that the dotty appearance hasn't extended outside the main dust lane area or into the background as is often the case in other more heavily deconed/waveletted images. Of course you have heard all this palava from me before I know and as I said still a great image in all other respects.

Mike

I agree with your philosophy. What I tried to do was keep it real by using the very hi res Capella image as a reference and ensuring that, if a detail appeared in my image it corresponded to something in the Capella image (see attached). The dots may actually be there in this case?

Originally Posted by Rex

Another Stunner Ray. Your images of late have been astounding. Great job mate!

Very generous Rex - thanks

Originally Posted by gregbradley

The repro is perfection to my eyes. Well done. Mightily impressive.

Greg.

I really appreciate your comment Greg - thanks

Originally Posted by nandopg

That is an outstanding image. The outter halo is nice and smooth as should be and the usage of multi-scale wavelet for sharpening the core is spot on.

One of the best n5128 I´ve seen.

Fernando

thanks Fernando - all the best

Originally Posted by multiweb

One for the cool wall Ray. You've surpassed marathon men in every aspect.

Thanks Marc. Perhaps the marathon men still rule... Anyway, they are driving us all to up our games and have made a tremendous difference to our hobby, so good on 'em.

Originally Posted by topheart

Hi Ray,

Yes, now it looks finished indeed!! I thought the first version was a bit under-processed as there was so much detail obviously hiding in the softer version....this is wonderful, the sharper more pronounced core and the soft smooth outer areas...... wonderful tracking by your scope and good seeing obviously giving tight stars.

Your current version is much much better than my attempt about 5 years ago: http://apod.nasa.gov/apod/ap100313.html
Your stars are so much better - more colour, no artifacts and your processing more natural.



Tim

thanks Tim - such generous comments from an APODer are much appreciated.

Attachment for Mike. Regards ray

[strongmanmike (Michael)]

Originally Posted by Shiraz

I agree with your philosophy. What I tried to do was keep it real by using the very hi res Capella image as a reference and ensuring that, if a detail appeared in my image it corresponded to something in the Capella image (see attached). The dots may actually be there in this case?
Attachment for Mike. Regards ray

Ah yes.. unless of course they did the same thing ...

It's a fabulous image Ray, I think you know I think that just musing over some processing ideas, t'is all

Looking clear as a bell here, have flexed off tomorow morning soooo, I'm going out tonight with some fresh inspiration caus'o you so thanks a miwion buddy

Mike

[LucasB (Lucas)]

Super image Ray. A real inspiration!

[gregbradley]

I am not sure what the concern is about decon. Its a valuable tool. I haven't seen any artifacts from decon except if used too hard you get harsh star rings.
So like anything in processing easy does it. But I am curious Mike as to what artifacts you see or suspect? Minimum filter can create a wormy pattern that does not in fact exist in the image but not decon or at least the decon I am using (CCDstack, positive constraint 5 iterations, auto select stars is quite mild).

Ideally I would prefer not to use it but it has its uses. One is when one colour sub has larger stars and you do decon on that colour channel only so you don't get bad coloured halos (tip from Marcus a few years back - very handy thanks Marcus). Also the multi scale decon technique from Ken Crawford is useful at times on a galaxy image.

Greg.

Originally Posted by strongmanmike

Ah yes.. unless of course they did the same thing ...

It's a fabulous image Ray, I think you know I think that just musing over some processing ideas, t'is all

Looking clear as a bell here, have flexed off tomorow morning soooo, I'm going out tonight with some fresh inspiration caus'o you so thanks a miwion buddy

Mike

[strongmanmike (Michael)]

Originally Posted by gregbradley

But I am curious Mike as to what artifacts you see or suspect? Minimum filter can create a wormy pattern that does not in fact exist in the image but not decon or at least the decon I am using Greg.

It's the dotty looking detail (and often backgrounds), that's all, ie. when the details all start to look like various sized (mostly small) circular dots or thin worms it looks pretty obvious to me.

Not a biggy and as I said just light processing chatter

Mike

[Harel_Boren]

Lovely Centaurus A through and through! What can I say that hadn't been said: great detail, wonderful halo, lovely starfield. A feast to the eye. Sheer delight!
Cheers,
Harel

[gregbradley]

Originally Posted by strongmanmike

It's the dotty looking detail (and often backgrounds), that's all, ie. when the details all start to look like various sized (mostly small) circular dots or thin worms it looks pretty obvious to me.

Not a biggy and as I said just light processing chatter

Mike

I'll keep an eye for that as I hadn't really noticed it. So the background starts to look spotty. Yes I think know what you mean. I think that only happens with noisy data with low SNR to start with and if Decon is too heavy.

It'd be worth having a thread about decon. I am sure there are prerequisites for it to be successful. Like anything in processing it usually assumes enough data so that the shot noise is reduced. Its probably showing up the shot noise as if it were a real signal.

Greg

[Shiraz (Ray)]

Originally Posted by strongmanmike

Ah yes.. unless of course they did the same thing ...

It's a fabulous image Ray, I think you know I think that just musing over some processing ideas, t'is all

Looking clear as a bell here, have flexed off tomorow morning soooo, I'm going out tonight with some fresh inspiration caus'o you so thanks a miwion buddy

Mike

thanks Mike - hope it turned out well

Originally Posted by LucasB

Super image Ray. A real inspiration!

thanks very much Lucas - appreciated

Originally Posted by Harel_Boren

Lovely Centaurus A through and through! What can I say that hadn't been said: great detail, wonderful halo, lovely starfield. A feast to the eye. Sheer delight!
Cheers,
Harel

Thanks very much Harel - appreciate your generous comments.

regards Ray

[RickS (Rick)]

That's a very classy 5128, Ray!

[tilbrook@rbe.ne (Justin Tilbrook)]

Great work again Ray!

I think the first image has the edge, just seems crisper overall.

How many subs did you reject if any?

I usually just eyeball each sub, probably not the best way.

Cheers,

Justin.

[Shiraz (Ray)]

thanks very much Rick and Justin.

Justin, I dropped about 1/3 of the subs due poor FWHM. Used Fits Image Grader to sort them - really handy bit of software.