This minor odd radius came with a surprise after stacking. Outside the 18° halo / plate arc there seems to be a faint, but rather well defined 20° column arc. As there is no sign of 9° stuff, crystals had no middle prism which is rather rare situation. The display was observed on August 9 in Kontiolahti.
![20° column arc](https://www.ursa.fi/blogi/ice-crystal-halos/wp-content/uploads/sites/9/9_August_09_ana_small-720x320.jpg)
Hey Marko,
I did the tif conversion and did a stack of the display that had 9,20,22,24,and 35d rings well theres also 18d ring as well and the 35d ring is long and colorful. Problem is though when I USM with photoshop and try to save copy as JPG it wont let me do that.
Michael,
You need to flatten the image and transform it into an 8 bit image. I suppose this is the problem. JPG does not support 16 bit image data.
I the bit depth or the flatting is not the answer, then you need to give us a little more details of your process.
Nice one ! Here the August has been lack of halos. But on 15th I got my first upper sunvex Parry arc. The brightness was uniform with the tangent arc.
Shoot Marko I got simultaneous concave and convex parry arc one a couple years ago.
Congrats on first sunvex Parry Krusel. Not an easy catch in high clouds. Even upper suncave is quite rare with naked eye.
That is pretty accurate simulation I must say ! How many frames ? What halo forms were visible with naked eye except the 20 column arc ?
When Marko first saw it there was 18 and 23 degree rings with upper 23d plate arc.
That’s just 25 frames. The display faded away. With naked eye I saw 23 and 18 arcs.