Analysis of the sky background found that the OIII stacked image was 1.2X brighter than the corresponding Ha stacked image.
This meant there was a bias towards OIII in the enhancement process and less Ha detail coming through in the masks.
Normalizing the OIII background relative to the Ha background has resulted in a better balanced image with a cyan appearance corresponding to the OIII emission and more red Ha detail near the core.
The white core is mainly due to near ultra violet.
Reprocessed image.
http://members.iinet.net.au/~sjastro...III_Ha_new.jpg
Steven
