Very strange interference colors on ice
Taken by Mika-Pekka Markkanen on February 21, 2018 @
Senja, Norway
Click photo for larger image
| |
Camera Used: Unavailable Unavailable
Exposure Time: Unavailable
Aperture: Unavailable
ISO: Unavailable
Date Taken: Unavailable
|
|
| More images
Details:
One year ago last winter I came across this fantastic opportunity to skate on a natural untouched ice of a pond by the sea and surrounded by mountains on the arctic island of Senja in N-Norway.
At some point I noticed these strange colors near the Sun's bright reflection and luckily I had my camera and tripod with me so I managed to capture some nice photos of the phenomenon. (No camera or polarizing filter was needed to see it though!)
Afterwards I've been trying to find out what it is that I witnessed and captured. Experts I contacted and amateurs and professionals on devoted forums were all puzzled and nobody seemed to have clear answer. It seemed like no one, not even Les Cowley, had ever even seen such a thing before!
The man who made the most effort in finding out was color expert Dietrich Zawischa, a retired Prof. Dr. from the Institute of Theoretical Physics of Hannover University. Here's some quotes from him from our e-mail exchanges and a link to the detailed explanation he made eventually: "I have never seen this phenomenon of colourful arcs on ice, and I never saw a similar picture. Such beautiful natural ice is very rare, and I guess that this optical effect is so uncommon that it has not yet got a name. I would call it "a strange interference pattern on ice". It puzzles me a lot and I have no explanation ready."
"I now think it is just the peculiar grainy surface of the ice which is responsible for the colours. The structure might be due to some snow falling just when the water was going to freeze while the weather was very calm.
Presumably the rays reflected by neighbouring grains interfere."
"Let me thank you again for your question and your enigmatic pictures! Though I was not able to reach full agreement in a simulation, I think I got the essential physics of the phenomenon."
Here's the link to Prof.Dr.Zawischa's eventual explanation attempt with detailed calculations and models: https://www.itp.uni-hannover.de/fileadmin/arbeitsgruppen/zawischa/static_html/strange2.html#coloursonice
Camera gear and settings:
Nikon D750 & Nikkor 24-120mm f/4 + tripod
Hoya HD Cir-Pol-filter (did not affect seeing the phenomenon)
Settings: 24mm - f/8 - 1/2500s - ISO 100
Photographer's website:
http://instagram.com/mpxmark
|
|
|
