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View Full Version here: : IC 4628 Prawn Nebula in SHO


Startrek
02-06-2024, 05:20 PM
I haven’t image the Prawn Nebula since 2022 and back then I was using my 2600MC OSC. The Prawn Nebula was well placed throughout May and captured around 10 hrs of data over 3 nights using my 2600MM and Antlia 3nm SHO filters.Most of the data was captured during a waning moon.

Captured over 3 nights ( 10 hours integration)
Waning Moon 75% to 25%
Seeing conditions poor to average ( high humidity )
Heavy dew after 9pm on all 3 nights
Bortle 8 City suburban skies
8”f5 Klaus Helmerich Carbon fibre Newtonian Reflector
Skywatcher EQ6-R pro mount
ZWO 2600MM cooled to -10C , Gain 100
ZWO 7x2” EFW
ZWO EAF
Orion 60mm guide scope with helical focuser
ZWO 120MM guide camera
PHD2 Multistar guiding ( total error avg 0.50 to 0.60 arc sec )
Antlia 3nm Filters
Ha 75 x 3min dithered subs
Oiii 60 x 3min dithered subs
Sii 62 x 3min dithered subs
Darks frames from Library
Flats Ha , Oiii and Sii
Flat Darks Ha, Oiii and Sii
Analysed , Calibrated, Stacked and Aligned in ASTAP
Processed in Startools V1.8 via Compose
Colour HST / SHO preset with saturation and colour bias adjustments
Didn’t capture RGB stars , instead used Startools Shrink module with a Star mask and adjusted colour taming and halo extend parameters. Not perfect but Stars are good enough for me considering it’s an SHO palette.
All 3 nights had heavy dew setting in early ( around 9pm ) so used my Kendrick heater band on the guide scope which works a treat but heater bands on carbon newts don’t work very well , so decided to use my 400mm pedestal fan and blew air over the Newt all night. It worked surprisingly well and allowed me to image through to the early hours. I didn’t think it would work but it did , and over 3 different nights where humidity was above 85%. That old fan is now apart of my Astro kit.

Quite pleased with the final image considering condition's

Link to Astrobin for full resolution……..,

https://www.astrobin.com/j4c5ig/

Original frame version reduced res 200kB
Crop version for a closer look reduced res 200KB

Comments welcome
Thanks for looking
Martin

Dave882
02-06-2024, 11:56 PM
Martin that's a superb prawn! The detail is wonderful and carefully processed and the colour pallet is gorgeous, bright and really engaging. Framing is really nice too. Honestly a really lovely result through and through.
I've been on a similar wavelength to you the last week and pulled in a few days of narrowband data on the prawn (albeit a much smaller fov :P) - and yes the conditions have been very challenging of late. Still fussing with the data but hopefully will finish things off and post soon...

MarkInSpace
03-06-2024, 07:59 AM
Very nice! Your images prove you can get incredible images from an 8” telescope.

gregbradley
03-06-2024, 09:36 AM
That turned out very well.

I like the colour palette.

Greg.

Bodon
03-06-2024, 09:53 AM
Really nice photo Martin! :thumbsup:

Startrek
03-06-2024, 01:07 PM
Thanks Dave
Lovely comments
You should have seen the initial Auto stretch , quite noisy which didn’t surprise me. I could see a brighter glow in the northern sky more than usual , you guessed it , “Vivid”
I decided to use another stretch option in Startools called Film Dev which is based on the old digital develop algorithm. It seems to work a bit better with noisy data.
SV Decon also worked quite well considering I throttled up the iterations to 15 ( default is 10 ) took quite a bit of blur away without adding too much noise mottle. It’s a great algorithm, more natural than AI based Decon
The damn dew was ridiculous over those nights. I’m glad I tried the old fan , it really worked which surprised me and didn’t upset guiding at all as it’s a constant movement of air not gusts.
Thanks again
Martin

Startrek
03-06-2024, 01:11 PM
Thanks Mark,
8” f5 CF is a versatile Newt for all round imaging.
Glad I stuck to f5 years ago , a snack to collimate , holds collimation well and not too many issues with image train regarding stars etc..
My 10” f5 CF in my Dome down south is a ripper scope , blows me away every time I use it.

Martin

Startrek
03-06-2024, 01:12 PM
Thanks Greg !

Startrek
03-06-2024, 01:12 PM
Thanks Steve !

Davidpmcadam
03-06-2024, 02:51 PM
Martin,
Another excellent image.

Retrograde
03-06-2024, 04:39 PM
Very good Martin.

It isn't usually the prettiest nebula in the sky (IMO) but it looks quite lovely here. Nice and deep and I really like the colour pallette you've used. :thumbsup:

Startrek
03-06-2024, 07:14 PM
Thanks David
How are you going with your imaging set up ?

Startrek
03-06-2024, 07:23 PM
Thanks Pete,
Yes I agree it’s not the most spectacular nebula but very unique all the same with some really nice pockets of detail.
Under B8 skies and moon glare my Oiii subs were just stars , couldn’t see any hint of nebulosity but it’s definitely there, just need a load of hours to expose it.
The colour palette is your typical HST Hubble with golden hues and blue / cyan blends. The outer regions of nebulosity are a tad reddish but intentional.

Cheers
Martin

strongmanmike
04-06-2024, 01:06 PM
That's one VPP Martone (Very Pretty Prawn :D). I really like the hue of blue you have settled on and the brightness maintained in it, has a lovely glow, nice work buddy :thumbsup:

Mike

Startrek
04-06-2024, 04:22 PM
Thanks Mike,
Yeh I got a bit adventurous and pumped up the bright saturation to make the image pop without sacrificing too much detail , obviously it worked by the number of lovely comments , yours included.
Long weekend is looking a bit sketchy for Astro down south , maybe Saturday night ??
Anyway it’s still nice to get away with the misses and enjoy our coastal retreat ( this time without the grandkids for a change ) a bit of kayaking up out local inlet , beach walking , bush walking , eating out , feeding the king parrots and lorikeets from our decking , ah the joys of retirement.
Anyway enjoy your time on top of the mountain , maybe a few ports to warm the soul

Cheers
Martone

strongmanmike
04-06-2024, 04:32 PM
Yeah, pretty annoying huh?, especially considering how good the last Full Moon period was :rolleyes: :mad2: aaaarg!...Oh well, as you indicate, plenty of other cool things to do...errr?..in my case, arhem... mostly involving beer :D

Mike