NGC 3324 Gabriela Mistral Nebula

[Startrek]

Captured a quick hour and half on NGC 3324 whilst testing my mount after adjusting the worm drives earlier in the day
Seeing average
Intermittent Patchy cloud
No moon
Bortle 3
NexDome Obs
8”f5 GSO newt
Skywatcher EQ6-R mount
ZWOASI2600MC Gain 0 cooled to -10C
Baader MPCC
Optolong L Extreme filter
30 x 3 minute dithered guided subs
40 x Flats
50 x Bias
Tracking and Goto EQMOD and Ascom Stellarium
Framed focused and captured with APT
PHD2 Multistar guiding
Stacked in DSS
Processed in Startools V1.7 ( Compose OSC/ DSLR Bi Color )
Colour module Matrix 2 x SHO Bi Color versions

Comments welcome

[Mike in Rancho]

Nice!

Having never seen this pretty object before, that I know of, I had to look it up on Stellarium. Seems to be an unreachable DEC for me.

What is a SHO bicolor though?

[Startrek]

Thanks !
NGC 3324 is a Southern Hemisphere object ( part of the Carina Nebula which is the largest observable nebula )

Bi colour is achieved through loading data sets into Compose

Here’s my write up

Compose OSC Bi Colour Images for Emission , Reflection and Planetary Nebula using L Extreme filter

Open Startools and use “Compose” to load data set

Select Luminance Colour - L+Synthetic L from R (2xG ) B, R ( GB) (GB) ( Bi Colour from OSC DSLR )

Load your data set into
R / S11
Green / Ha
Blue /Oiii

Leave Luminance file None
Color Channel Interpolation On
Channel sliders are set to default or 1hr 3600sec ( no need to adjust )

When loaded press Keep , then choose Linear

Start your normal workflow in Synthetic Luminance or Mono until you hit the Colour module

Colour Module
Style Scientific ( Colour Constancy )
Saturation Amount 180% to 250%
Bright Saturation + 2.0 to taste
Dark Saturation + 2.0 to taste
LRGB Emulation Try both RGB Ratio CIELab Luminance Retention and Straight CIELab Luminance Retention
Bias Slider Mode - Sliders Reduce Color Bias
Red Bias 2.0 to 3.0
Green Bias 3.00 to 4.00
Blue Bias 1.20 to 1.60

The above settings are only a guide. Green bias must be reduced and Blue bias increased to obtain a good Bi Color image. Adjust as necessary.

The above should result in a good Bi Colour image when using the SHO Options in the Matrix at the bottom right

Generally for HOO , HHO, OOH options in the Matrix , reduce the Red bias, increase the Green bias and leave the Blue bias similar to SHO options.

For Interpolate and RGB options in the Matrix , again adjust the Red bias and Green bias to taste. Normally the Blue bias can remain between 1.20 to 1.60

Hope the above is helpful

Clear Skies

[Mike in Rancho]

Thanks.

No I have an L-eNhance and have done countless bicolors, and indeed plenty of times I have reverted back to Color Constancy from the bicolor preset of Artistic. Also the B and G bias are "additive" in their operation on the (BG) loaded into both B and G. That is, a reduce of 2.0 G and 1.0 B is the same as 1.0 G and 2.0 B, or whatever other equal permutatons you can come up with. So it seemed in my experiments, anyway. Also, per Ivo, the sliders (in bicolor or tricolor) are actually tied to the emission filters regardless of the hue mapping.

I'm just trying to think what you meant by "SHO bicolor." Do you mean using the tricolor matrices? Obviously I've used HOO, and frequently the one other "normal-ish" alternative of H(H+O)O. But I would need to think through what it would mean to compose the R(GB)(GB) at the outset, yet then map into a tricolor and begin adjusting the sliders, and if the emission integrity holds.

[Startrek]

Mike,
To achieve those Bi colour images I loaded data set into Compose R, G , B , select L+Synthetic L from R (2x G)B,R (GB)(GB) Bi Color from OSC DSLR. Save as Linear
Process through until you hit Color
I tried both Scientific and Artistic Aware modes
In Color use the Matrix at the bottom ( I used the 3rd and 4th colour option mapping )
Then tweaked the R, G, B bias sliders to taste
Also adjusted bright and dark saturation to taste
Left Saturation to default 200%

Hope the above helps
Clear Skies

[Mike in Rancho]

Thanks again!

I understand the process, was just trying to confirm that you were compositing bicolor but then selecting tricolor mappings from the matrix. This, plus the newest image and description you posted, does seem to confirm that.

As far as I can tell, I am still only seeing two hues. Still trying to think through exactly how the channel mappings are built and/or should be considered, which is the subject of another open thread so I may have to wait on that, but I may also just try to get out a notepad and see if I can figure out how it is all coming together and being adjusted by the sliders here. Possibly the duplicated B/G already keep things properly on track.

Gracias still!