Sunday 16 August 2009

20° column arc


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.

8 comments:

  1. 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.

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  2. 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.

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  3. 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.

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  4. Shoot Marko I got simultaneous concave and convex parry arc one a couple years ago.

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  5. Congrats on first sunvex Parry Krusel. Not an easy catch in high clouds. Even upper suncave is quite rare with naked eye.

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  6. That is pretty accurate simulation I must say ! How many frames ? What halo forms were visible with naked eye except the 20 column arc ?

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  7. When Marko first saw it there was 18 and 23 degree rings with upper 23d plate arc.

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  8. That's just 25 frames. The display faded away. With naked eye I saw 23 and 18 arcs.

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