Nice shot Bert, certainly a lot going on in there!
It is interesting seeing the difference between the Ha and SII, most filters tend to combine the two
As Spock would say, Fascinating!
Really interesting result, I for one would love to see this with OIII as well instead of the Synthetic channel. Just a thought...
This was just an exercise to see if there was any difference between 3nm NII and 3nm HA filters. There is some speculation that there is leakage between the two depending on frequency or wavelength shifts due to angle of incidence variation on the filters. This is also a matter of focal ratio where the myth is that F3 has too much angle of incidence variation.
The green channel was the NII and HA data stacked as an average with rejection to give some sort of rational baseline.
The differences are subtle but real in the red and blue channels. The best test is the contrast of unrelated structures in the top left corner where slightly blue gas clouds cross obviously red ones.
This is not a map of gas concentration. For monatomic Nitrogen to emit the 'forbidden' N[II], stimulation from nearby hot blue stars is needed in the UV.
I will do a full Hubble Palette and RGB with this area.
