Merging monochrome L & OSC RGB from 2 DSLR's...

[Phil Leigh]

Hi,
I have a rather vague question...
I have two cooled, modded DSLR's both based on the Canon 1100D. One has been professionally debayered and so is a 12Mp monochrome (luminance) camera, the other still has its Bayer CFA intact.

I'd like to combine images of the same target from the two cameras.

I have suitable master dark & master bias from both cameras and 2 sets of flats and lights.

Calibration/alignment/integration for each set is straightforward.... remembering to debayer the OSC images at the correct point in the workflow of course!

So, my question is; what can I do with the two "master" images? - what are the options for combining them?
Also, I sometimes additionally use an Ha filter on the mono camera (so I have 3 "master lights" - Ha, Luminance and RGB)

Are there any links/resources/suggestion to help me get my head around the options for processing this data into a final full colour image?

many thanks
Phil

[Carlos Milovic]

Take a look at the LRGBCombination process.

[astroedo]

Hi

I've not experience in this, so take this as an idea to develope.
You can try to separate RGB layers from the color image and align them with the L image using L image as reference (using Dynamic alignement or Star alignement).

Then you can put all together using LRGB combination or pixelmath.

For the Halpha issue you can read this interesting post from Juan (http://pixinsight.com/forum/index.php?topic=3734.0
): it is intended for Narrow band combination, but i suppose can be used as a tutorial on using Pixelmath for channel combination.

Hoping to be useful

Ciao

[Phil Leigh]

OK - thank you ...lots to research there.
The one thing I am confused about - and really I guess the root of my question...

The 12Mp mono (greyscale) image is 12Mp of Luminance, but (before debayering) the OSC image is 3Mp "Red", 3Mp "Blue" and 6Mp of "Green" - I know there is some bleeding across the colour filters...

Do I split the RGB image into three channels before or after debayering - and how do the different numbers of pixels tie up across the L, R,G & B sub-images (I may not have explained this very well...)

I can see how it works with a single mono camera and LRGB filters...
Thanks for any insight you can provide - maybe I should just experiment?

[Carlos Milovic]

Just debayer the CFA image to create a RGB, and incorporate the luminance from the "clear" image. Of course, they must be previously registered. I would register the RGB image to the luminance. No need to split the image.

I think that you should need to color calibrate the RGB image before performing the LRGB combination. Also some people prefer to process separately both image, and merge them in the nonlinear stage.

[Phil Leigh]

Excellent - thanks Carlos!