Sh2-132 Lion Nebula, HOO

[KathyNS]

Sh2-132 Lion Nebula, using my modified HOO palette, which has a little bit of Ha blended into the green channel.

Orion 200mm f/4 Newtonian
Atik 383L+

29x 600s Ha, 1x1
13x 900s Oiii, 1x1

[helicon]

Very nice Kathy!

[Gmetric]

That's a beauty, Kathy. The orange glow gives it a lovely sense of warmth and depth. Very nice

[MistrBadgr]

I have not seen that one before. Nice rendering! Thanks for sharing!

[messier 111]

very pretty, beautiful colors.
I like the depth, thank you.

[Graeme1858]

Yeah, great depth Kathy.

Regards

Graeme

[MariusD69]

Awesome! Great job, Kathy!

[STEVE333]

Nice job Kathy. That's a tough target especially with only 8 hrs total integration time. Well done.

Steve

[lostone]

Nice target

[Baskevo]

Wow Kathy! This looks absolutely stunning. I really love the blue color... Are you just using a standard HOO pallet, or are you using pixel math to use a custom pallet with Ha and Oiii combined?

[KathyNS]

Wow Kathy! This looks absolutely stunning. I really love the blue color... Are you just using a standard HOO pallet, or are you using pixel math to use a custom pallet with Ha and Oiii combined?

I use a modified HOO palette. I like the fact that HOO is similar to natural colour, but I find the pure version too stark. I use PixelMath to blend the colours.

red = 1.5 * Ha - O3
green = 0.4 * Ha + 0.325 * O3
blue = O3

The red formula is very unconventional: that minus sign is not a typo. Even with much longer exposures, my Oiii signal tends to be weak and buried in the noise for most nebulae. Subtracting it from the Ha signal prevents the latter from overpowering the Oiii. But, since I am thereby reducing the Ha, I have to amplify it with the 1.5 factor. I run the risk of saturating the Ha signal, but it hasn't happened yet.

The blending of Ha and Oiii in the green channel is what produces the post-apocalyptic oranges that I like. I suppose that, since there is more Ha than Oiii in the green, I should call it modified HHO. But I think the results are closer to the red-blue of HOO than to the yellow-blue of HHO.

I only use these formulae on starless images. I process the stars separately, using straight HOO, to avoid saturating them. Or else, I replace them with RGB stars, if I have them.

[jthommes]

Beautiful image Kathy. Well done.

[Baskevo]

Wow Kathy! This looks absolutely stunning. I really love the blue color... Are you just using a standard HOO pallet, or are you using pixel math to use a custom pallet with Ha and Oiii combined?

I use a modified HOO palette. I like the fact that HOO is similar to natural colour, but I find the pure version too stark. I use PixelMath to blend the colours.

red = 1.5 * Ha - O3
green = 0.4 * Ha + 0.325 * O3
blue = O3

The red formula is very unconventional: that minus sign is not a typo. Even with much longer exposures, my Oiii signal tends to be weak and buried in the noise for most nebulae. Subtracting it from the Ha signal prevents the latter from overpowering the Oiii. But, since I am thereby reducing the Ha, I have to amplify it with the 1.5 factor. I run the risk of saturating the Ha signal, but it hasn't happened yet.

The blending of Ha and Oiii in the green channel is what produces the post-apocalyptic oranges that I like. I suppose that, since there is more Ha than Oiii in the green, I should call it modified HHO. But I think the results are closer to the red-blue of HOO than to the yellow-blue of HHO.

I only use these formulae on starless images. I process the stars separately, using straight HOO, to avoid saturating them. Or else, I replace them with RGB stars, if I have them.

Very cool! I will have to try this in my next processing session Thank you for sharing Kathy!