M16 Ha

[Rodd]

The powers that be wanted me to begin this project.  I was going to collect more Ha for my Sh2-112 project, or NGC 6888 image, but a bank of clouds moved in.  Seeing was poor anyway, so I was going to pack it in when I noticed that the southern horizon was cloud free.  M16 was in perfect position--never gets higher than 35 dgerees, but I decided to take a few subs to plan a future project.  A few subs turned into 34 300 sec subs as the skt stayed clear over the target--pretty amazingly.  Seeing remained poor, however.  The FWHM of the stack is 4.1, well above what I normally choose to keep.  But, as withered winter apple is better than a barren pantry.    This data has been bined 3x3, and still there has been no resolution loss--a testament to the porrness of the data.  I could bin it by 8 or 10, but then I am left with a tiny image I might have well have collected using a 4" refractor.  Maybe I should switch to a refractor....the days I get to use the C11Edge as designed are very few and far between.  My guiding was decent for the conditions--.6-.8 total rms errors, and focus was good.  Tghe high FWHM must, therefore, be primarilly due to poor seeing.  My guide exposures were 8-10 sec, which was the duration that yielded the best guiding.  For some reason there are bright pixel issues.  I have eliminated as many as I could.  I am hoping they were a byproduct of the binning process and not a problem with my sensor.

C11Edge, 0.7x reducer, ASI 1600, binx3 in software.  34 300 sec subs

 

[Rodd]

A few tweaks. I find little adjustments with the edit tool on my iPhone yield improvements if care is taken not to overdo.

[vlaiv]

You have tons of SNR there.

Maybe some selective sharpening to tame those stars?

[Rodd]

Tame them?  They are bright but I did that on purpose because after I reinserted the stars they looked pale and weak.  I find this true when I use Starnet. So I bumped them up a it.  I think I forgot and sharpened after the stars were put back without a mask.  I will work on it.  I am actually surprised at how decent the stars look for staring out with a fwhm>4

Edited June 18, 2022 by Rodd

[vlaiv]

1 minute ago, Rodd said:

Tame them?

Probably wrong term - I was thinking of taming their extent / size rather than brightness.

 

[Rodd]

1 minute ago, vlaiv said:

Probably wrong term - I was thinking of taming their extent / size rather than brightness.

 

Well, here is best I can do on iPhone. Remember, they had a starting fwhm >4.1.   As I collect more and hopefully better subs the stars will get tighter.

[Rodd]

I think the original is best.   Oh well. Not bad gif what normally is tossed

[pipnina]

Beautiful image! One of my favourite objects, and yet also one that I do not have the horizon to image myself (hill is in the way) : (

If you could remove the stars with starnet, then perform a wavelet sharpening (multiscale linear transform in Pix, or "contrast by detail level" in rawtherapee) on the star-removed image, it might bring out that little bit of extra sharpness in the fine details.

 

[Rodd]

9 minutes ago, pipnina said:

Beautiful image! One of my favourite objects, and yet also one that I do not have the horizon to image myself (hill is in the way) : (

If you could remove the stars with starnet, then perform a wavelet sharpening (multiscale linear transform in Pix, or "contrast by detail level" in rawtherapee) on the star-removed image, it might bring out that little bit of extra sharpness in the fine details.

 

Yes. Good ideas. I am looking forward to completing this one

[Rodd]

I found an old Jpg I had from a few years ago--I don't have the data becuase my hard drive crashed.   But Experimenting is one of my joys.  I incorporated the new Ha into the image, which required allot of adjustments to get it to fit.  The old image was taken with tghe TOA 130.  Registered the TOA image to the new Ha

 

Edited June 19, 2022 by Rodd

[Shibby]

Nice - the seeing will of course be worse the lower the altitude, but you're lucky - it only reaches 25deg here!

[Rodd]

47 minutes ago, Shibby said:

Nice - the seeing will of course be worse the lower the altitude, but you're lucky - it only reaches 25deg here!

Thats M8 and M20 for me--about 25 degrees.  Its a shame becuase all of these low targets are in teh worst part of my sky