NGC 6188 - Dragons with an Egg...

[Drac0 (Mark)]

Yet another work in progress of what is my favourite early winter target. NGC 6188 - the Dragons of Ara, along with NGC 6164, their cosmic Dragon Egg...

Another bi-colour image with the green channel being a combination of the Ha & OIII, using about 4.5 hours for each filter. This will get plenty more imaging time over the coming months if the weather ever decides to co-operate. I think this is one of my better post-processing efforts.

All images captured using APT - Astro Photography Tool (www.astrophotography.app)
https://www.facebook.com/groups/1643360112557489

[carlstronomy (Carl)]

Super nice! Lovely colours and detail, I think your processing is really nice on this one. Keep doing what you are doing, can not wait to see the finished image.

Carl

[Startrek (Martin)]

Mark,
Nice work and love the colour palette too on quite a dim and challenging target
Well done !!
Martin
PS: I don’t know if your focus was slightly out , the larger star looks like it has split spikes , just an observation ?

[Drac0 (Mark)]

Thanks Carl.

Thanks Martin,

I don't think it's a focus issue. I've checked the full size original and double spikes only appear on that one star. Not sure why...

Cheers,
Mark

[Startrek (Martin)]

Looking at the next largest stars , they too seem to have double spikes or odd spikes ? Viewing at 200Kb is not ideal I suppose , could be my crappy eyes
Collimation , focus and spider vanes not being at wings level or equal alignment , focus tube obstruction and primary mirror clips obstruction are the major causes of issues with odd star spikes.
Is your scope an f4 as the spikes look like your typical f4 Newt ?

Cheers
Martin
Each to their own but I went f5 from the very beginning and so glad I did , I’d be too frustrated trying to dial in my 10” at f4.

[AstroViking (Steve)]

Very well done, Mark.

A suitably dark and moody interpretation of everyone's favourite dragons. Well done for getting the 'egg' in there, too.

Cheers,
V.

[Drac0 (Mark)]

Thanks Steve,
I think I've done much less processing on this than I have in the past when trying to make the background blacker with a lot of contrast. I think this looks much better. The change from a refractor to the shorter focal length newtonian allows me to get the Egg in the same image.

Martin,
How much are you zooming in? I'm going to 200% on the full sized original & not seeing more double spikes. Though I am wondering about the little black flecks on the image.

Cheers,
Mark

[Startrek (Martin)]

Originally Posted by Drac0

Thanks Steve,
I think I've done much less processing on this than I have in the past when trying to make the background blacker with a lot of contrast. I think this looks much better. The change from a refractor to the shorter focal length newtonian allows me to get the Egg in the same image.

Martin,
How much are you zooming in? I'm going to 200% on the full sized original & not seeing more double spikes. Though I am wondering about the little black flecks on the image.

Cheers,
Mark

To be honest I’ve never seen this before , however they are pixels that are not assigned but in a fixed pattern , possible dead pixels
Maybe some sort of thermal noise ?
They don’t look like hot or cold pixels
Definitely signal / sensor related !!!
What camera are you using and is it cooled ?
Q: Have you dithered your subs , used flat darks to calibrate your flats , used darks ?
Maybe someone else has experienced this type of output ?

Sorry can’t offer any further advice.

[Drac0 (Mark)]

Originally Posted by Startrek

To be honest I’ve never seen this before , however they are pixels that are not assigned but in a fixed pattern , possible dead pixels
Maybe some sort of thermal noise ?
They don’t look like hot or cold pixels
Definitely signal / sensor related !!!
What camera are you using and is it cooled ?
Q: Have you dithered your subs , used flat darks to calibrate your flats , used darks ?
Maybe someone else has experienced this type of output ?

Sorry can’t offer any further advice.

No idea either Martin.

ASI294MM PRo cooled to -5°C
All subs dithered
Darks (32), dark flats (30) & flats used (30)

Will have to check if it was something during the processing that may have caused it.

Cheers,
Mark

[Doogs38 (Alex)]

I really like this image Mark, and I tried to emulate your framing with the Egg albeit I needed a 2 panel mosaic. In my view, you’ve done *very* well with the Egg - it’s a feint target that’s hard to pull out (as I’ve learnt recently). Alex

[Drac0 (Mark)]

I really like this image Mark, and I tried to emulate your framing with the Egg albeit I needed a 2 panel mosaic. In my view, you’ve done *very* well with the Egg - it’s a feint target that’s hard to pull out (as I’ve learnt recently). Alex

Thanks Alex. Used to image this with a 102mm refractor & even with a 0.8x reducer it just wasn't quite wide enough to get both framed as I liked without going to 2 panels. The 150mm newt gets it nicely.

Cheers,
Mark