IMPORTANT UPDATE:
THE COLOURED BANDS TURNED OUT TO BE A RAW CONVERSION ARTEFACT. THIS WAS DISCOVERED THANKS TO JARI LUOMANEN AND THE HALO REPORTS BLOG. DETAILS AND DISCUSSION ON THIS OBSERVATION CAN BE SEEN AT http://www.ursa.fi/blogit/haloreports/index.php?title=22_halo_on_snow_surface_with_horizontal_&more=1&c=1&tb=1&pb=1
I'VE INCLUDED JARI LUOMANEN'S CONVERSIONS WITH CANON DIGITAL PHOTO PROFESSIONAL AND THESE JPEG'S, ORIGINALLY FROM 16 BIT TIFF CONVERSIONS FROM THE ORIGINAL RAWS DO NOT SHOW THESE COLOURED BANDS. PICTURES AND COMMENTS BELOW.
On December 21st, a halo display showed up over a frozen body of water, having a thin cover of snow and hoar frost.
The easy part is the regular halo. Inside there are no reflections from the ice crystals at all. The halo itself is colourful shifting from reddish-yellow to bluish-purplish to the outside. Outside the halo, there are reflections of the crystals everywhere, but most occur close to the halo.
Now the difficult part: outside, and slightly through the halo but not inside it, broad horizontal bands of cyan and magenta. They look a bit like Quételet bands.
I included a simple figure of how the display looks like so you know what to look for in the picture.
Note that the pictures have been enhanced strongly to show the display well. The halo and bands were visible with the naked eye, but a photograph shows less detail than the real thing. To show the details of the display better I increased saturation extensively and brought down the brightness of the ice and snow leaving the brightness of the reflections.
OK, SO I FEEL LIKE A COMPLETE IDIOT HERE. THERE WERE MORE THAN 10 DAYS BETWEEN OBSERVATION AND THE CONVERSION AND CREATION OF THIS PAGE. I REMEMBER SEEING A HORIZONTAL DARKER BAND ON THE ICE, WHICH MADE THE HALO A LITTLE LESS BRIGHT. IT SEEMS THAT THE DARKENING I SAW FOR REAL AND THE COLOURING THAT SHOWED UP IN ALL OF THE PICTURES MIXED UP MY MEMORIES. I WOULD STILL SAY I SAW THE COLOURS, EVEN THOUGH I KNOW NOW I COULDN'T HAVE SEEN THEM. MAYBE I SHOULDN'T GO OUT AND DO FOTOSHOOTS WHEN ILL AND UNDER PAINKILLERS. OR MAYBE I'LL HAVE TO LET MY BRAINS EXAMINED IF I DON'T WANT TO END UP HAVING MEMORIES OF BEING ABDUCTED BY ALIENS.
UNDERNEATH JARI LUOMANEN'S CONVERSION
UNDERNEATH JARI LUOMANEN'S CONVERSION
AS YOU CAN SEE BELOW, HE ALSO SAW THE BANDING COLOURING IN THE RAW CONVERSION PREVIEWS, BUT THEY DID NOT SHOW UP AFTER CONVERTING THEM TO 16 BIT TIFF FILES WITH CANON DPP. BUT THEY WILL SHOW UP IF YOU EXPORT TO 16 BIT TIFF OR PSD WITH LIGHTROOM OR PHOTOSHOP!
SO BE CAREFUL WHEN RENDERING YOUR FILES, ARE UNLIKE ME, LOOK VERY CAREFUL WHEN YOU SEE A DISPLAY AND DO NOT RELY ON WHAT IS SHOWING UP AFTERWARDS IN PROCESSING THE IMAGES.
PICTURES BELOW ONLY HAVE VALUE FOR THE HALO AND SCENERY. ALL HORIZONTAL BANDED COLOURING IS DUE TO RAW CONVERSION ARTEFACT
Underneath a cut-out of an image showing all colours are present in the reflections, but some more than others, creating the bands
cut-out
An original picture as shot without enhancement, Eos 5D RAW, picture style: neutral.
