This second version differs in the mapping of the HA, SII and OIII wavelengths.
The LRGB channels consists of HA_HA_OIII_SII, so if see green in this image,
it indicates presence of oxygen, blue is indicative of sulphur, red of ionized hydrogen (HA).

There are two versions. This is the 2nd one and it utilizes a different pallette from
The Hubble pallette I used on the first at http://www.pbase.com/steelnavy/image/81778146

The Hubble pallette, assigns (or "maps" in current parlance) SII to red, HA to green,
and OIII to blue. This mapping is necessary because the light emitted by SII and OIII
is not visible to the human eye, so assigning these light frequencies to visible
wavelengths lets one "see" where SII and OIII present in the image.

In both images HA consists of 180 minutes of exposure with 10 minute sub-exposures.
SII and OIII each consist of 120 minutes in 10 minute subs. All imaging done on bright,
near full moon evenings.