I've done this before a year ago but the conditions were pretty good and having the new camera with stable OAG plus small pixels and it's such a cool neb in NB...I went for her profile once again
This is a Bi-Colour (Ha OIII) image with some RGB mixed in
I enjoyed some quite good seeing for the Ha but just average seeing for the OIII (did I mention I want to move to Chile? )
Beautiful work there Mike. Did you consider lowering the intensity of the bright inner blue region? I think you'd get a really cool strong blue hue in there as a result, but I don't know how bright it really is compared to the rest so just an idea
Youve done well their young Mike, lots of detail and appropriate saturated colour. Im not sure the bicolour thing worked though, even bad Sii would have made it a bit less bitonic. Im not sure why you dont use darks really, given they are easy to collect and last a good year if your lucky. They are stupid easy to apply during processing and would give you that slight less noise edge to allow more confidence in processing.
Very nice indeed Mike! As I mentioned on Flickr, thanks for sharing what is on the other side of the clouds - it's always a tremendous pleasure!
Cheers,
Mario
No worries Mario and grazzie for your kind comments, it isn't everyone's cup of tea and often hard to please everybody
Quote:
Originally Posted by alpal
Nice shot Mike.
You've got a lot of detail in there.
cheers
Allan
Thanks Alan yes I was happy with the seeing on that night, see guide star centroid plot from a few sub sets across the night... and that certainly helped with the details
Quote:
Originally Posted by SkyViking
Beautiful work there Mike. Did you consider lowering the intensity of the bright inner blue region? I think you'd get a really cool strong blue hue in there as a result, but I don't know how bright it really is compared to the rest so just an idea
Thanks for the suggestion Rolo, I did try a few version incluidng making that aea darker but I may have another tinker...Arggg another Sidonio might be coming
Quote:
Originally Posted by telecasterguru
Quite striking.
Frank
Thanks Frank, glad to have struck you
Quote:
Originally Posted by Stevec35
Not quite sure I like the colour Mike but technically nice in every other respect.
Cheers
Steve
No probs Steve, this narrowband thing is a little fickle and I did decide to miss the SII and only go Bi-Colour but don't think this object works with the traditional Red-Blue look that the Ha-OIII combo usually gives...? so I tweaked it with some layer mixing magic
Quote:
Originally Posted by Bassnut
Youve done well their young Mike, lots of detail and appropriate saturated colour. Im not sure the bicolour thing worked though, even bad Sii would have made it a bit less bitonic. Im not sure why you dont use darks really, given they are easy to collect and last a good year if your lucky. They are stupid easy to apply during processing and would give you that slight less noise edge to allow more confidence in processing.
Thanks Fred, yeah I hear the Botonic thing, I tried to counter that by tweaking the bi-colours with the RGB but in the end there are only two main data sets I guess and this was the outcome...?..I was happy with the nice blue OIII wisps in the fainter areas, remind me of floating thin cirrus As for the darks?...As an older generation Kodak chip user it would be hard for you to understand but the Sony chip and in this particular camera architecture simply doesn't need them and in fact adding them (and/or flats and flat darks) is actually likely to make the noise level more ...I was quite happy with the noise level in this image though..?? and that was with no noise reduction, just dithered lights and median combine.
Thanks Fred, yeah I hear the Botonic thing, I tried to counter that by tweaking the bi-colours with the RGB but in the end there are only two main data sets I guess and this was the outcome...?..I was happy with the nice blue OIII wisps in the fainter areas, remind me of floating thin cirrus As for the darks?...As an older generation Kodak chip user it would be hard for you to understand but the Sony chip and in this particular camera architecture simply doesn't need them and in fact adding them (and/or flats and flat darks) is actually likely to make the noise level more ...I was quite happy with the noise level in this image though..?? and that was with no noise reduction, just dithered lights and median combine.
Hi Mike,
It's a nice Gabriela for sure.
But I have to agree with Freddy a bit, it could be better.
I looked at the larger images and some of the stars (Top RHS of the Ha image) are a bit not round, they seem to be elongated in a diagonal way. I even put on my glasses to make sure it wasn't my eyes. As your seeing and guiding were good, perhaps there's been a misregistration. I find that CCDStack sometimes does this in very dense star fields.
The image doesn't need darks as you have dithered, so they'll be eliminated mathematically as long as you get enough subframes for the mathematical rejection to work. But it could be sharpened a bit. Louie Atalas has a great tutorial on using PS to do deconvolution. I tend to go a bit overboard WRT sharpening, but as long as you're not introducing stuff that isn't there then you're just correcting out the atmosphere.
Colour is the choice of the photographer in NB imaging. Even more so with bicolour. Look at mine, those wisps of OIII have turned green because of the way I treated the Ha data.
We should compare Ha images. Essentially the same scope design, mostly the difference would be atmospheric, though I can't remember the weather when I took my Gabriela.
Great colors. I don't understand why you don't do flats or darks. Darks I never did with my QHY8 that wasn't temperature regulated but for sure flats are important to get rid of dust motes and uneven illumination.
the Sony chip and in this particular camera architecture simply doesn't need them and in fact adding them (and/or flats and flat darks) is actually likely to make the noise level more
Hi Mike, I didn't notice noise in particular and your images with the new cam have all been great, so the following is purely from a theoretical point of view:
Why would darks introduce noise (unless you didn't have enough dark frames)?
And I'm wondering about flats too, because regardless of the chip you'll always have at least a degree of natural vignetting, due to the light rays striking the outer areas of the chip at an angle (pixel sensitivity depends on the angle of the incoming light). There will be dust doughnuts too, at least eventually.
Once you'ce created a dark/flat library there should be no extra effort required in applying this step to all your data. The calibration can be automatically applied in software like Maxim, so just thinking why wouldn't you always calibrate your data and squeeze the most from your camera?
So, not saying that your images need any of the above, but ideally I guess we'd all love to get the most from our equipment.
But I have to agree with Freddy a bit, it could be better.
Aint that always the truth
Quote:
I looked at the larger images and some of the stars (Top RHS of the Ha image) are a bit not round, they seem to be elongated in a diagonal way. I even put on my glasses to make sure it wasn't my eyes.
Well, yes, I guess under extreme scrutiny almost any system will reveal something imperfect, in fact and even though it is not displayed at full res and to me it doesn't matter, the stars are not uniformly round in your shot either nor in Rolfs if you look closely...it's the nature of our beasts but it doesn't detract from the overall visual experience in my opinion, we can become way too fixated on optical perfection rather than imaging sometimes Newtonians are indeed very hard to get absolutely perfect in all situations, especially fast ones, but never the less produce arguably superior sharper looking images to many RC's and certainly to SCT's, of significantly longer FL
Quote:
The image doesn't need darks as you have dithered, so they'll be eliminated mathematically as long as you get enough subframes for the mathematical rejection to work.
Yes, agreed, hence why I don't need them given the low noise levels on the chip
Quote:
But it could be sharpened a bit. Louie Atalas has a great tutorial on using PS to do deconvolution. I tend to go a bit overboard WRT sharpening, but as long as you're not introducing stuff that isn't there then you're just correcting out the atmosphere
Hey, perhaps you are right... but in the end it is a processing choice and the level of sharpening is usually an aesthetic choice in most cases rather than actually revealing real extra details without looking noisy. I did try sharpening more during processing of the main bi colour image (I worked out how to use the decon better in Astroart ) but yes, as you say with your version (sorry) it looked slightly "over" sharpened and didn't actually show any more real "features". I decided I liked it looking ever so slightly soft rather than super hard edged...all the same features are still there - again just a choice .
Quote:
Colour is the choice of the photographer in NB imaging. Even more so with bicolour. Look at mine, those wisps of OIII have turned green because of the way I treated the Ha data.
That's it, nail on head Work Choices ...... argggg run for your liiiives, they are being brought back to life, dug-up and un-cremated
Quote:
We should compare Ha images. Essentially the same scope design, mostly the difference would be atmospheric, though I can't remember the weather when I took my Gabriela.
The seeing was pretty good for my Halpha
Thanks again for taking the time to make a worthwhile response
Last edited by strongmanmike; 11-03-2014 at 09:54 AM.
Great colors. I don't understand why you don't do flats or darks. Darks I never did with my QHY8 that wasn't temperature regulated but for sure flats are important to get rid of dust motes and uneven illumination.
Quote:
Originally Posted by SkyViking
Hi Mike, I didn't notice noise in particular and your images with the new cam have all been great, so the following is purely from a theoretical point of view:
Why would darks introduce noise (unless you didn't have enough dark frames)?
And I'm wondering about flats too, because regardless of the chip you'll always have at least a degree of natural vignetting, due to the light rays striking the outer areas of the chip at an angle (pixel sensitivity depends on the angle of the incoming light). There will be dust doughnuts too, at least eventually.
Once you'ce created a dark/flat library there should be no extra effort required in applying this step to all your data. The calibration can be automatically applied in software like Maxim, so just thinking why wouldn't you always calibrate your data and squeeze the most from your camera?
So, not saying that your images need any of the above, but ideally I guess we'd all love to get the most from our equipment.
I do agree about the flats but not the darks actually as I use dithering. There are indeed sensitivity variations across even this lovely Sony chip and yes probably some very slight optical brightness variations that flats might address but the flats and flat darks will add noise. Luckily I have no dust motes though, even under hard heavy stretch so at the moment at least flats are not required for these
In the end I think your first sentence there says it all Rolf
I may of course buckle under all the pressure to conform...
Great work, Mike. Love the details. The Hubble comparison shows you done good The colours are OK but not entirely to my taste.
Cheers,
Rick.
Hey cheers Ricki , the Hubble comparison is pretty bloody good for a 12" 1120mmFL F3.8 Newt for sure but it also shows me that I'd dearly love some longer focal length for these good nights hmmm? I neeed a system that can convert from F3.8 to about F6.8 or so...hmmm? Might have to splash out on an ASA 1.8X Barlow, they will work perfectly with the AG12
)
another Sidonio might be coming 
and that was with no noise reduction, just dithered lights and median combine.
but it doesn't detract from the overall visual experience in my opinion, we can become way too fixated on optical perfection rather than imaging sometimes 
) but yes, as you say with your version (sorry) it looked slightly "over" sharpened and didn't actually show any more real "features". I decided I liked it looking ever so slightly soft rather than super hard edged...all the same features are still there - again just a choice 
...
hmmm? I neeed a system that can convert from F3.8 to about F6.8 or so...hmmm? Might have to splash out on an ASA 1.8X Barlow, they will work perfectly with the AG12 
