[Placidus (Mike and Trish)]

Our angry bee (NGC 1769, NGC 1763 for eyes) is still lacking SII. Tomorrow night looks promising. But in the interim, just mucking around with Ha + OIII only. The things that tug on one when choosing a mapping:

- That it looks familiar and makes sense to a viewer used to Hubble Palette where Ha is mapped to green and OIII is mapped to blue
- That it doesn't look harsh and implausible to someone used to natural colour, where Ha would be red, OIII teal, and there might be some blue H-beta in there as well.

Personally, we both find attempts at a purely natural palette (Hydrogen magenta, OIII teal) very unpleasant, with echoes of butcher's apron, cryovac liver, and abdominal surgery gone wrong, so we'd like to avoid that.

Here are two possible solutions. The left hand thumbnail maps Ha to yellow (that is to say both its natural red and Hubble green), but OIII is mapped only to Hubble blue. That is legitimate scientifically, but looks pretty harsh.

The right hand thumbnail is "naturalized" just a tiny bit, by rotating the palette of the first image 15 degrees toward red (ie -15 deg in PhotoShop). That way, there is a nod toward Ha being red and OIII being more teal, and a half a nod toward H-beta. This is still valid scientifically because the original image can be recovered by rotating the palette 15 degrees clockwise with no information loss.

Given that "pure nature" is out, and "straight hubble" is out, since good SII can be hard to find, we'd love to know which of the two compromises you prefer.

Peter Ward might notice that there are three beautiful irridescent goldfish all riding on the bee's back. The middle of the three is very convincing.

Ha 8hrs, OIII 8hrs, 3nM in 1hr subs. Aspen CG16M on 20" PlaneWave. Field 36 min arc, North up.

Best,
M & T