Are these good stacking results?

Hi, first of all excuse my grammar but English is not my native language.

I’ve been using Siril for quite a few versions and I’m fairly familiar with the processes of staking full spectrum targets, but now I just got and testing a Duo band narrow band filter for OSC, and the stacking result of Heart Nebula confuses me :neutral_face:

This is 300" 1sub red channel:

And these are the Green

The signal of every channels are the expected, with strong Ha signal in red channel, and average Oiii signal in green channel :ok_hand:

but the results after stacking is a suppressed signal in red channel, and much stronger in the green channel, and I dont know why?.

Stacking result in Red channel, expected much more signal than this in Red channel:

Now after the stacking the Green channel is the dominant :thinking:

Shouldn’t be the red channel the one with the most signal after the stack or am I missing something?

Thanks in advance.

Hello and welcome!
For a dual band filter, you should use the OSC_Extract_HaOIII.ssf script instead, it will create two images, one for Ha and one for OIII.

Anyway, what you are seeing is related to the noise levels in your images. Autostretch display depends on the histogram, which depends on the noise level. After stacking, you can’t really know which will be the brightest. Cameras are more sensitive in the green, but there may be more signal in Ha…