Adding Blue to Triffid

[billhinge]

I'm reasonably happy  with the detail  on the Triffid , I  like the textured  look but  since the  image is Ha, OIII and UV there is not much reflection nebula so  I  took  a normal Blue  filtered image.

Is  it possible  to easily add the Blue layer minus stars to the  narrowband image?

There are 2 images 1 from  PI, the  other from PS by the way

I want to retain the Herbig-Haro jet  but reduce the blue halo on some stars if possible

feel  free to play I'm at a loss as  to what direction to go in

FinalView.tif Blue2.tif FinalViewPS.tif

Edited August 30, 2020 by billhinge

[billhinge]

This is another version, Ha=L, SII=red, OIII=green, Blue=Blue

Part   of the problem I think is that I have SII, Ha, OIII, UV and  Blue and I'm  not sure what the best mix is?

Ideally I  would get the blue nebula minus stars from the  last image and add it to the first

[MarkAR]

Lets have a look at what SHO is like, Oiii is mainly around the outside. Leave out the UV and Blue.

[billhinge]

This is straight SII=red Ha=green  OIII = blue, no multipliers etc 

SHO.tif

[MarkAR]

The data looks good, next step is to remove the green, any gradients and noise, then tweak the colours etc.

I would stick to working in PI to start with. Then if you need to, final tweaks in PS.

I would do:

1. SCNR

2. DBE (sometimes if the data is really good you may not need to do this, see if it gives a better or worse result)

3. Create Mask for stars and nebula, add together with Pixelmath to mask the stars and nebula then de-noise the background.

4. Use a star mask to reduce the stars a little if necessary. (Don't thing you'll need to but worth trying)

5. Use the nebula mask to smooth, de-noise or sharpen the nebula.

6. Run the Dark Nebulosity script (works very well)

7. Final curves tweaks for colour/ saturation etc.

With any stretching be careful not to clip the black or white points, clipping the black too much will result in the loss of the finer details.

[billhinge]

Thanks  Mark

By dark nebulosity do you mean dark structure enhance? I do use that sometime with default values

When you say nebula mask, I assume you are talking generally about a PI mask rather than a 3rd party script download of that name (I'm using latest 1.8.8.6)

Thanks for the clipping tip

[MarkAR]

Yes Dart Structure Enhance.

Yes a PI Range Mask or use a clone and Starnet to remove stars then use that as a mask.

Once you've run SCNR you should have a Red/Blue colour nebula. If the stars are a bit magenta then invert the image and run SCNR on Green again, re-invert and it will remove magenta.

[billhinge]

Cheers Mark, 

I'm using a macbook and just installed starnet++ for masks, seems quite nifty 😉

 

[MarkAR]

Starnet is now built in to the latest version under Process.

[billhinge]

you have to add the dylib kexts and weight files manually on a mac and do a bit of security config afterwards

[ollypenrice]

Your plan to de-star the blue then add it to the image is potentially sound but I'd do it in Photoshop. Also I would only add it to an HaOIIIOIII which had been processed to replicate natural colour in RGB (though there wont be much blue yet.) I don't think there is any sane way to mix false colour and natural blue so I'd start with HOO, as I say.

I'd then de-star the blue and stretch it so that the background sky was a point lower than the background in the NB image. That way it won't slew the sky colour. I'd then add it to the blue channel in Blend Mode Lighten.

I don't know if it would work but at least it's logical.

Olly

[billhinge]

Thanks Olly, I'll give that a go later. I  just discovered starnet so having a play with that and pixelmath at the moment 😉

(I'm into the whole python, deep-learning AI subject)

Edited August 31, 2020 by billhinge

[billhinge]

I  kind of got the shape I wanted but not sure about the colour 😁

This is a  mix of reflected blue from OIII and UV, the central pink Ha is also high in UV (Astrodon UV photometric), I wanted to map out UV  areas  so part pretty pic, part scientific