Despite a never ending series of poor seeing sessions since March, I managed to get enough (mediocre) data to finish this off. I think it's a respectable result for a relatively small object, but it was a battle - I used 39 subs and threw away 41 subs that were worse than 3 arcsec FWHM).
Has turned out a treat Marcus, nicely resolved and good colour.
Out of curiosity, what it did look like if you ran more than 50% of the subs together? I suppose it largely depends on what the FWHM of the subs you kept were
What a luxury, to be able to throw data away It is a small object, nice result.
Terry
Thanks Terry. Not a luxury - a massively frustrating and extremely annoying waste of time. Onwards and upwards though!
Quote:
Originally Posted by RickS
Very respectable, Marcus! Some lovely detail in the cores.
Cheers Rick!
Quote:
Originally Posted by Atmos
Has turned out a treat Marcus, nicely resolved and good colour.
Out of curiosity, what it did look like if you ran more than 50% of the subs together? I suppose it largely depends on what the FWHM of the subs you kept were
Thanks a lot Colin! Adding any of the rejected subs (3 to 5 arcsec FWHM) simply reduced detail and contrast with faint stars and background galaxies. As it was, it was a struggle to show what you see in this image.
Quote:
Originally Posted by IanP
It's a very respectable result, Marcus. Great shot
The galaxy itself looks pretty good. My CDK is also quite sensitive to seeing so its just one of the limitations of this type of imaging short of putting it on a mountain. Narrowband though seems to cut through the seeing quite well.
The galaxy itself looks pretty good. My CDK is also quite sensitive to seeing so its just one of the limitations of this type of imaging short of putting it on a mountain. Narrowband though seems to cut through the seeing quite well.
Greg.
Cheers Greg. A mountain would be nice but I'd settle for 900m or so!
Quote:
Originally Posted by Placidus
Crispy sharp in the core, deep feathery antennae. Everything one could want. Beautiful colour too.
Thankyou M&T! Glad you like it!
Quote:
Originally Posted by Paul Haese
The detail and colour in the core is very nice Marcus. The rest is just more data as you know. Still good given the struggle.
Thanks Paul.
Quote:
Originally Posted by strongmanmike
Well, this image sounds like it has been a bit of a trial for you Marcus? ...some nice details showing in the central areas none the less
Mike
Cheers Mike! Don't get me wrong, I'm happy with it but I know I can do better if the conditions cooperate. You make the best with what you're given though, right?
Quote:
Originally Posted by topheart
Good job Marc, especially considering the poor seeing .....hope Sydney gets better seeing where you are soon.
Cheers,
Tim
Very nice, Marcus! Nice colour and excellent detail in the galaxies.
The antennae look pushed a bit hard for my tastes, the transition to the background seems too abrupt when looking at the full res.
I recently found good use of bad subs by integrating two sets of data: the good subs, and all the subs. I then made a mask out of a stretched copy of the "all subs" integration (which had bigger stars, blurrier detail), and then replaced the higher signal areas of the image with the good set.
Granted, it doesn't solve all the world's problems, but it did mean that I got a much cleaner background, while preserving detail in high signal areas. Good to smooth out things like the antennae as well.
very nice work Marcus, love the resolution in the core. annoying about the subs!
Thanks Russell!
Quote:
Originally Posted by codemonkey
Very nice, Marcus! Nice colour and excellent detail in the galaxies.
Thanks Lee.
Quote:
Originally Posted by codemonkey
The antennae look pushed a bit hard for my tastes, the transition to the background seems too abrupt when looking at the full res.
Fair enough. It can be a difficult balance to get the transition of such faint elements to be as smooth as they are in reality without megadata. I opted for showing as much as I can with a mere 9 hours of data, even showing faint stars blurred by bad seeing. It can also be a function of the monitor your using too but I'm assuming you have a calibrated monitor. You can check contrast & brightness settings here:
Quote:
Originally Posted by codemonkey
I recently found good use of bad subs by integrating two sets of data: the good subs, and all the subs. I then made a mask out of a stretched copy of the "all subs" integration (which had bigger stars, blurrier detail), and then replaced the higher signal areas of the image with the good set.
Granted, it doesn't solve all the world's problems, but it did mean that I got a much cleaner background, while preserving detail in high signal areas. Good to smooth out things like the antennae as well.
Blending bad subs with good subs is fraught - especially when it comes to the faint background stars and galaxies. Isolating them from the blurring effects of bad subs very problematic.
Last edited by marc4darkskies; 15-06-2016 at 08:02 AM.
I think it looks very nice. If you could outline which program you stack your data or how you determine each frames fwhm data that would be great. I know its basic but I use Deep Sky Stacker and it gives me a fwhm value but mine are just huge. I don't think I have seen below 3 or 4 sadly. I also capture using MaximDl. Thanks.
More than acceptable Marcus - I think it's very nice. I hear you about bad seeing. It's generally the norm in my part of the world.
Cheers
Steve
Thanks a lot Steve! I usually get a smattering of good seeing nights, but not lately. Hmmm, I would have thought Canberra would have better seeing conditions on average than here.
Quote:
Originally Posted by batema
I think it looks very nice. If you could outline which program you stack your data or how you determine each frames fwhm data that would be great. I know its basic but I use Deep Sky Stacker and it gives me a fwhm value but mine are just huge. I don't think I have seen below 3 or 4 sadly. I also capture using MaximDl. Thanks.
Cheers Mark! I use CCDStack for calibration, stacking and initial deconvolution. It shows FWHM in pixels. For a more reliable measure I use CCDInspector which measures FWHM in arcseconds (with appripriate parameters describing your optical configuration).
Quote:
Originally Posted by DaveNZ
Good work Marcus. Nice colour and good detail even though seeing was average.
It is a small object, nice result.
Has turned out a treat Marcus, nicely resolved and good colour.
Onwards and upwards though!
...some nice details showing in the central areas none the less 
