What a difference a year makes! (NGC 4945)

[marc4darkskies]

Inspired by Paul Haese's cool image and Mike Sidonio's Sidonio, I went back and revisited my year old NGC 4945 image with my recently learned decon layer blending technique to see if I could improve the fine detail. Previously, my approach to sharpening was quite blunt (pun intended) as it tended mostly to accentuate contrast and, in fact, obliterate fine detail.

Attached are the before (left) and after (right) versions (250% enlargement of a small section of the frame) - the increase in detail is quite remarkable!

For the full frame see:
http://www.pbase.com/gailmarc/image/110479642/original

Cheers, Marcus

[Bassnut]

Yes, needs a direct AB comparison, but the Sid is indeed better, no processing artifacts I can see, top work.

The full frame is impressive, very nice work, in fact quite exceptional.

[marc4darkskies]

Fixed up the star colours now too :D



Thanks for that Fred!

[allan gould]

Getting tips from others really helps proficiency in processing astro shots. Really makes a great difference and well done Marcus. A great shot with subtle detail.

[JD2439975]

Big difference in detail Marcus & the full frame is glorious. :thumbsup:

This latest collection of 4945's has really opened my eyes as to how colourful & lovely this galaxy can be.

[strongmanmike]

I compared this same piece of galaxy to that in my latest version and have concluded that your before image and mine have pretty much identical feature resolution with some things more apparent in mine and some things more apparent in yours (only slight differences) but what ever you have done with the decon layering in your latest version has upped the res anti somewhat :clap:.

See?? doing a Sidonio is often well worth it, why some people roll their eyes at the practise I have no EYEdear :P

As I said in my reply to your post in my latest 4945 thread, your image of 4945 is one of the finest of this galaxy I have seen, maybe even the finest? :)

Mike

[telecasterguru]

Most interesting image and lots to think about in the processing game.

Frank

[RB]

Wow, a big difference indeed !
Excellent work Marcus, the image just seems to snap into focus if you blink between them.

:thumbsup:

[Garyh]

I like your decon layer :eyepop:
What a difference, Must learn that one!

[Lester]

Fantastic improvement Marcus. The finer detail just snaps into focus. Makes me wonder how much more detail is in their just waiting to be revealed, as processing improves even further.

All the best.

[marc4darkskies]

Thanks Allan! Giving good tips is actually quite hard because the workflow for processing each image is slightly different. The baseline steps though are quite consistent and it's certainly true that learning how to use deconvolution effectively (using CCDStack in my case) is a must.



Thanks Justin. It's certainly one of the more colourful that's for sure. You may have noticed I named the image "Galactic Campfire" for the glowing ember look it had about it.



Thanks Mike - very high praise indeed! I'm sure you'll find a way to up the ante again though ;)



And you never stop climbing the processing learning curve Frank. And just when you think you've got it mastered you take a picture that stumps you (for a while at least :)) or you discover a new technique that helps you take it to a new level.



Thanks Andrew. I actually went back and did the same trick with my M83 image (http://www.pbase.com/gailmarc/image/96834475/original). A definite improvement but somewhat more subtle - I guess I must have nailed the sharpness better the first time round.



Yep it's a must have in your repertoire! See http://www.rdelsol.net/ProcessingToolBox/ProcessingTool%20Box.html



Thanks Lester. Nah, no more detail there - short of imaging under very dark skies with sub arcsec seeing I think I've about reached the limit.

[Paul Haese]

Marcus that is a lovely compliment but your image is vastly superior to mine. I need to get my luminence on a night when the focus does not change so much. Your level of detail is stunning. Not overly sure about the colour scheme but the detail is superb.

[gregbradley]

Wow Marcus, that is just superb. You did everything just right with that one.

Thanks for linking Ken's tutorial on multi layer deconvolution. Very good data.

I managed to setup doing my TEC180 at F11.2 using a TOA 1.6 extender.
I wasn't sure if it managed greater resolution with only one image as a test.
Apart from a larger image scale do you think it makes for greater resolution?
And if it does, then does it require extra hours to show that extra resolution?

Roland Christen in the past has posted that long focal length with refractors can
produce very high resolution. I couldn't see any advantage in my 1 image test
but it was very limited as a test.

Cheers,

Greg.

[marc4darkskies]

Thanks Paul - but I wouldn't say mine is "vastly" superior at all ... yours is a fine image! Moreover, I reckon yours is close to my original in tems of resolution. And look look at what I did with the same data and slightly improved processing. Maybe there's hidden info in your data as well?

You may be surprised to know that I stayed true to the original colours in the raw RGB combine - except for some additional saturation of course. Admittedly I don't do proper G2V calibration either, preferring to trust my eyeball to discern good colours in a close up star field (ie red, white, blue and yellow stars ... and no green!) and a neutral sky background.



Thanks Greg!

Well, unless you have seeing that is much better than your 180's native image scale (1.5 arcsec per pixel), then you won't see an increase in res. Better image scale is good though - makes it easier to apply decon or other sharpening techniques. Of course if you get skies with sub arcsec seeing then you'll be laughing! Will you need longer exposures? The photon flux/pixel must be lower with the extender but not by very much so in the real world I'd say exposures won't need to be longer. Having said that, I usually err on the side of longer subs anyway - but that's more superstition than anything :lol:

Cheers, Marcus

[gregbradley]

Thanks Marcus. Makes sense. After a certain point of excellent optics and aperture we are limited by seeing.

Greg.