2011. április 28., csütörtök

Faint odd radius halos

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Now here is an example of a display where you see nothing special visually. Just a faint 22° halo that is a bit brighter from the top. But there was one visual clue, however, that revealed it might be an odd radius display. It was the broadness of the 22° halo. And indeed, in the photos 9° halo is seen as well as 18/20° halo. The outer halo might not contain 22° halo at all, rather, it can be 23/24° halo.

Had I had a convex mirror, the 9° halo would certainly have showed up with it, also the 18/20° halo. The two photos above are versions of one. They are 2 minutes stacks. The date is 28 April 2011.

The display just continued and one could have gotten several hours stack of it. When in the afternoon 9° halo was visible to the naked eye, I took another stack in the middle of tyre changing. The third image has 7 frames taken during about 2 minutes. There is 35° halo (arrow), it is seen also in single images, which means it would have been observable with convex mirror.  Fourth image is a bit longer stack. Now the 35° halo is on the other side.

2011. április 27., szerda

Non-spotted Wegener arc

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Not seeing a colored Wegener when it is there can hollow a halo man up. Just that's what happened today. There was a nice little display little in cirrus and I found Wegener from the photos afterwards. It is actually rather typical for me to not see them.  Curious incidence was that I took a panorama of the same clouds earlier when they were closer to horison and not yet at halo making distance. I did not expect them to show anything special.

Hugin is good now for halo panoramas as it gives 16 bit output. I put here also two different projections of the cirrus cloud panorama. The first is cylindrical and sencond is rectililnear. The rectilinear represents the clouds more like they appeared to the eye, being straight stripes.

2011. április 6., szerda

Lunar diamond dust halo display in Rovaniemi, 7/8 December 2008

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Before the moon halos appeared, diamond dust was so thick that moon did not shine through and I photographed in spotlight beam. As the the diamond dust started thinning, it also lifted up from the ground - there were not much crystals on the ground. The moon elevation is about 30 degrees judging from the circumzenith arc which is slightly separated from the 46 halo.