Which colour palette do you think works best?

[MLParkinson (Murray)]

This series of M16 images was created by mapping different wavelengths to the RGB channels. Which colour palette do you think works best?

Televue NP127is Refractor @ f/7.8 (1.5x extender), QSI683wsg camera, Astronomic SII, H alpha, OIII and Blue filters.

Higher resolution versions:

http://www.flickr.com/photos/mlparkinson/8246634156/

[LewisM]

2nd, followed by the 5th. The rest look false too much.

[Ross G]

Hi Murray,

They all seem to have about the same detail.

The second one looks the most "natural".

However, my favourite is the monochrome photo.

Ross.

[ourkind (Carlos)]

Its a tie between the 2nd and 5th.

2nd has nice contrast beween nebulae and molecular clouds.

But I find the 5th and monochrome versions the cleanest and clearest.



Nice image too!

[MLParkinson (Murray)]

Thanks for the feedback. These few simple comments really do help. I need some reality checks. My sense of the aesthetic is obviously different to most people and I really should start thinking about what other people like. I think that I know what people mean when they say “natural looking”. It is an approximation to the subdued colour we would probably see if our night vision allowed us to. Although I plan to produce some more natural looking pictures, I still think every deep sky image is a lie in the sense that it portrays an object in a way the human brain-eye combination could never truly see.

Image 1: H alpha only
Image 2: Red = Ha alpha, Green = (H alpha+2*OIII)/3, Blue = OIII
Image 3: Red = Ha alpha, Green = OIII, Blue = Blue
Image 4: Red = Ha alpha, Green = OIII, Blue = SII
Image 5: Red = SII, Green = Ha, Blue = OIII

[stardust steve (Steve)]

After much deliberation, #1 wins with the runner up #5
The rest of the combos never did anything for me. great image BTW

[jsmoraes (Jorge)]

Number 2 is more natural looking, smooth. Number 4, in spite of the apparent aberration, it shows better the main irradiations from nebula.

"I still think every deep sky image is a lie in the sense that it portrays an object in a way the human brain-eye combination could never truly see."

I don't know. I was never so nearby to see and to say !

[Jon (Jonathan)]

Taking as read the consensus as to "natural", I do find the detail of the wavelengths clearer to see in the Hubble palette image.

[MLParkinson (Murray)]

Some people produce stunning images using the Hubble palette, but I suspect that my M16 image is way too green (i.e., dominated by H alpha). My hunch is that the Hubble palette works best when imaging with larger apertures which can be used to achieve higher SNRs on the SII emissions. Then one can infuse the final RGB image with more deep red.

Even so, I still enjoy imaging in SII using my little 5-inch refractor because the filter allows the detection of stars which are invisible at shorter wavelengths. One really notices the penetrating power of SII in the raw images.

I guess someone will correct me if I've got it wrong

[Tandum (Robin)]

When stretching NB images you'll get a far more pleasing result if you don't stretch everything as far as you can, like RGB. Try stretching to balance the histograms.
Pick the weakest channel and stretch that out, normally SII, then stretch the other 2 channels to match.

Also have a read of this page:- http://bf-astro.com/hubbleP.htm

This is your image with the green knocked back a bit.