Trifid Nebula Narrowband advice

[billhinge]

Hi

I was just playing around with one of the remote iTelescope (previous called gras) scopes and decided to go for a shot at the Trifid in narrowband

This was 9 mins in Ha, 9 mins in SII and 24 mins in OIII on the Sidlng Spring T30 scope

I processed this in Pixinsight using pixel math (red = Sii + 0.3*Ha, green = Ha, blue = Oiii + 0.4*Ha) after a bit of trial and error

I realise I need a few more subs but there are a few questions

1 - any suggestions for next subs, it is already very bright in Ha after 9 mins so I guess more SII?

2 - any suggestions as to what pixel math combo's might be better

3 - in order to capture the blue reflection nebula, am I correct in thinking I need some subs through a blue filter?

This is a rough play in PI, if anyone wants the individual Ha, SII, OIII channels for play I'm happy to post them

[MeyGray3833]

Hi.

What sort of image are you trying to create?

If you want a traditional Hubble palette I would try the SHO_AIP script in PI unders Scripts > Multichannel Synthesis. If you are trying to blend the data to produce an RGB orientated image, I doubt you will get much in the way of reflection nebulosity. There are very few examples of narrow band Trifid images and most only show the top part with no hint of reflection nebulosity. You could always try a SHORGB blend to bring out the detail you want.

Other more experienced imagers may have more idea than me these are my thoughts based on my experience.

Hope that helps.

Graham.

[billhinge]

Hi Graham

I noticed apart from Hubble there weren't many, I'm a bit contrarian at times and like to be different

Thanks for the heads up on the scripts, I missed that, there are some really good scripts now (like the Repaired HSV Separation) . I'll have a look this afternoon

As to the look, well Hubble but unfortunately I'm struggling to get much blue

[billhinge]

I decided to follow my own thoughts so I added another 20 mins of Ha and 6 mins of B and UV, not finished yet but I think I can see what I want to do

so totals so far :=

9 min SII

29 min Ha

24 min OIII

6 min B photometric

6 min UV

next month I'll add some more Ha , B & UV and perhaps a bit of G to supplement the OIII

This is a rough hack in PI

PS the ccd bloom occurred on the 6 min Ha exposure and 3 min B exposure

[Gina]

Very nice Do you know what your problem is with the extra long diffraction spike? Green removal would help.

[billhinge]

Hi Gina

Yes the long spikes are due to blooming with a blue (B photometric filter - has a wider range than normal Blue) and the camera is a Non Anti Blooming Gate CCD so I will take some shorter B images and use the sigma clipping to reduce/remove them (hopefully - its worked before)

I was actually collecting OIII as green ;-), I'm using SII & Ha as red and B & UV for blue. On my monitor I'm not actually seeing much green?

here is a slightly different version that hopefully shows what I want the nebula core to look like, ie a lighter core emphasising the pillars and jets which is where the blue and green are brightest

[sologuitarist61]

Very nice!