Processing Ha image in gimp

[Chefgage]

I imaged the North American nebula in Ha using my  hydrogen alpha clip in filter. The images have been stacked and I use GIMP to process them.

The question is how to extract the red channel to then just process this. I have used the decompose to RGB with the decompose to layers option ticked. This then gives me a grey scale image to then process. Is this the correct way to extract the hydrogen alpha data to process?

 

[vlaiv]

I'd rather RGB decompose to separate images ... This will also give you mono image - use red channel of course.

[Chefgage]

24 minutes ago, vlaiv said:

I'd rather RGB decompose to separate images ... This will also give you mono image - use red channel of course.

Thanks vlaiv. So do you mean I should not tick the decompose to layers option.

[vlaiv]

53 minutes ago, Chefgage said:

Thanks vlaiv. So do you mean I should not tick the decompose to layers option.

Yes, I mean - that is how I usually do it - it separates into different images - then you can close off R and G image and just keep working on R image

(truth be told - you can do same with layer - just delete R and G layers - not sure if I contributed anything clever - both ways seem equally useful ).