HaRGB images are pink!

[micheleorsini]

Hello,
I am new to Ha + RGB photography and I'm finding troubles mixing Ha and RGB data.
I'm using a Canon 700D modded with a CLS filter when imaging RGB and with an Ha 12nm EOS clip when imaging HA
Inspired by the posts in the forum concerning mixing Ha and RGB data, I made several attempts without any satisfying result.

1. I used Startools for processing Ha and RGB stacking results separately (three channels processing for Ha too, not sure if this is the right thing to do)

2. then I splitted the Ha final image into R/G/B channels keeping only the R for next steps

3. I tried to mix results using LRGB module: I had to split the RGB final image in R,G,B and load them in the module, finally I loaded the Ha R channel as luminance

LRGB.jpg (416.98 KiB) Viewed 5141 times

4. I used the layer module: loaded the RGB image and used the Ha R channel as a foreground. I've tried several modes (for example: "brightness of fg", or, swapping the layers, "color of fg") and several brightness mask modes

Layer.jpg (461.04 KiB) Viewed 5141 times

In any case I end up with an image with more details as expected (resulting from Ha) but where the nice red regions of the nebula (see foreground layer above) become pink.

Can you help me?

[Guy]

Hi,

Have you tried the approach described by Ivo in the Mel 15 thread?
It is also described in the 'Special Techniques' section of Layer Module Use under the heading 'Combining Luminance and RGB Images'
Here the RGB is made luminance-independent (normalised) before combining with the luminance.
There is also a reference to an alternative approach using the LRGB module there too.
There is also a description there of using Ha + RGB to create a synthetic luminance frame.

The CLS filter will have an effect on the colour - but usually just to remove the yellows.

Guy

[micheleorsini]

Thank you Guy, using articles you posted the result is much better in colors!

I still have to understand better how to use all the Layer params but results are promising!

Also, the other layer module usages are really interesting, I'm going to make some tests with the new data

thank you again

Michele

[Guy]

Hi Michele,

I'm glad the articles have helped.
The Layer module is very powerful and I won't pretend to understand many of the options. If you find a good source of information I'd be very interested.
Also, If you discover anything that may be useful to others please let me know. I'm always happy to add useful tips to the Module Use posts.

Guy