Guys,
It's not the theory that worries me - I have that well understood!
What is being said is that imaging through various bandwidths ALLOWS additional light ( other than Ha) to get through from the star's continumm spectrum. This additional "stray" light has nothing what so ever to do with Ha; it may be SII or NII or background light....
I've used many narrow band filters for imaging and understand the challenges of focusing in the red... but it's NOT the Ha emissions as much as some other light to help either visualise or image with.
Enough from me! I'll go back to my spectroscopes and let you guys do the imaging!!
