The SII is assigned to the red channel, Ha to green, and OIII to blue.

This narrow band image of the Eagle nebula represents something of an experiment. I imaged the nebula through a set of narrow band filters as I have done before, but decided to try and add in some luminance to see if I could get some better detail and bring back the stars. Overall I would say that the stars have been reintroduced and are much brighter and numerous than with normal narrow band images. The detail is a bit subjective. I think that it is a little better, mainly due to the luminance and the better resolution used to take the luminance images. However, I do think that a little bit of the contrast that is a feature of the narrowband images has been lost. I would think that this is due to the general broad background light that is captured during luminance / clear filter exposures.