M22 Great Sagittarius Cluster

[Startrek]

Captured M22 Great Sagittarius Cluster back in early August during a waxing 50% Moon in Sydney
Almost forgot I had imaged it , found the data whilst doing some housekeeping on my Laptop
Not too many globs are presented on the forum but this is one of my personal favourites both imaging and observing it.

Bortle 7/8 Sydney Skies
50% waxing Moon
6” f6 Bintel GSO Newt
Skywatcher EQ6-R pro mount
TS Optics GPU coma corrector
ZWO2600MC cooled to -10C , Gain 100
No filters
45 x 90sec dithered guided subs
40 x Flats
60 x Bias
EQMOD, Stellarium, APT
Stacked in DSS
Processed in Startools V1.8 OSC Linear Data Set

Used the new Spatial Variant PSF Deconvolution module which worked really well on this cluster , tightened up all the stars and reduced “atmospheric blurring” Apparently this type of Decon is unique to Startools. Ivo is continuing working on these modules and this one’s a winner

Original Frame version
Crop frame version

Comments most welcome
Thanks

[strongmanmike]

Nice job, I love M22 as well, in fact, it's reasonably comfortably naked eye from Eagleview :D

One thing, the star field is actually quite dense around M22, have you tried stretching your data a little bit more...?

Mike

[Startrek]

Thanks Mike
After an initial AutoDev Stretch the glob was swamped by the dense Star field , you could hardly see it , so I used a ROI to maintain dynamic range around the glob and dampen or back off the Star field.Then used the Superstructure module to enhance the glob a tad and finally Spacially Variant PSF Decon
I agree, not an astronomically visually correct representation of M22 but being an astro image you want to highlight the central cluster area , otherwise the image is too washed out or whited out with stars ( a bit a creative licence on this one or is it called “processing” )

Cheers
Martin

[strongmanmike]

Hmmm?..ok, fair'nuf :thumbsup:

Mike

[Startrek]

Mike,

A quick reprocess of M22 with a more pronounced Star field and a tad more HDR to main cluster

A better representation ??

Original Frame
Cropped Frame
Super Crop

Cheers
Martin

[strongmanmike]

Yeah, I recon it is :) Suppressing stars is sometimes a good idea, say for enhancing nebulae structure or for a galaxy in a busy star field maybe? However and some may disagree, I recon Globs, especially those near the galactic plane, look good in a busy star field :)

Mike

[Ryderscope]

The re process has been a positive improvement their Martin. The cluster is still well resolved without being blown out whilst showing more of the surrounding context.

[Startrek]

Yep I have to agree , a bit too heavy handed on the first process
This one has more dynamics across the whole image now
Something to take away for the next Glob

[Startrek]

Thanks Rodney
Yes this repro is definitely better

Cheers
Martin

[Dave882]

Lovely glob Martin. Got lots of nice star colour too! Well done:thumbsup:

[Startrek]

Thanks Dave
Seems most folk don’t bother too much with globs and prefer the big emission nebula and HII regions for the Wow factor !

Globs especially the larger brighter ones aren’t as easy as you think to image , they still pose a challenge around the core areas and I enjoy imaging them

Cheers
Martin