I'd seen that sort of effect in a couple of renders (e.g. Lenny2's "Jewel" and the 'no postwork comment convinced me it had been done using atmosphere). My own attempt ("Will O'The Wisp" - mild nudity warning)  fell a bit short of the mark and needed postwork. Your last picture above is exactly what I wanted... but in green/yellow.  Thanks for the information on how you did it (using the edge blend seems a great touch!) - I need to fish out the scene file and try using your settings.  :)

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The 3Dcheapskate (also available in DAZ and HiveWire3D flavours) occasionally posts sensible stuff. Usually by accident.
And it usually uses Poser 11, with units set to inches. Except when it's using Poser 6 or PP2014, or when its units are set to PNU.