by Chris Peterson » Sat Jan 05, 2013 3:58 pm
owlice wrote:The halo was visible with the naked eye; the temperature was probably in the mid to upper 20s. The photographer was inside when she noticed the halo around the tree, so went outside onto the deck to take pictures of it. She did not notice the light by the foreground bush until she looked at the pictures, as she was so taken with the light encircling the tree. I don't know the duration of the halo, except that she says the halo was visible as long as the sky was pink.
I have three other pictures, all taken within about a minute or so of one another on an iPhone. I reduced this image slightly to post it here; I have not reduced the others and await permission to post links to them.
It isn't uncommon to have different kinds of snow around a tree- underneath, it is affected by tree litter and snow dropping from branches. Around the edge, the snow drops a little differently from branches, and sometimes drifts just a little. Snow under the tree, in a halo around it, and in the wider fields is all exposed to the Sun differently, and therefore can end up with different surface textures, as well.
I wish the photographer had examined and reported on the snow quality. My guess is that there is a ring of snow around the tree that has melted and refrozen, forming an icy veneer that is reflecting the sky, while the snow out in the open is just a little bit rougher, and therefore less specular.
[quote="owlice"]The halo was visible with the naked eye; the temperature was probably in the mid to upper 20s. The photographer was inside when she noticed the halo around the tree, so went outside onto the deck to take pictures of it. She did not notice the light by the foreground bush until she looked at the pictures, as she was so taken with the light encircling the tree. I don't know the duration of the halo, except that she says the halo was visible as long as the sky was pink.
I have three other pictures, all taken within about a minute or so of one another on an iPhone. I reduced this image slightly to post it here; I have not reduced the others and await permission to post links to them.[/quote]
It isn't uncommon to have different kinds of snow around a tree- underneath, it is affected by tree litter and snow dropping from branches. Around the edge, the snow drops a little differently from branches, and sometimes drifts just a little. Snow under the tree, in a halo around it, and in the wider fields is all exposed to the Sun differently, and therefore can end up with different surface textures, as well.
I wish the photographer had examined and reported on the snow quality. My guess is that there is a ring of snow around the tree that has melted and refrozen, forming an icy veneer that is reflecting the sky, while the snow out in the open is just a little bit rougher, and therefore less specular.