2011. május 21., szombat

Halos 20. May

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In the afternoon the clouds came. Parhelion was blindingly bright. I followed as the same cloud reached the 120° parhelion position and there was an intensity increase which soon attenuated. The last image shows two photos taken 88 seconds apart, the 120° parhelion is seen in the left photo, in the right photo the cloud has already moved further and the distant parhelion is no more seen. I think the best part of the cloud did not pass the 120° parhelion location, or it would have been brighter.

Day's halos:

  • 22° upper tangent arc

  • 22° halo (just a small patch in the second photo)

  • parhelia

  • pillar

  • circumznith arc

  • 120° parhelion

2011. május 2., hétfő

Sun pillar in Stratocumulus virga (and an attempt of fake sun), 1. May

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In the spring, when there is a break of cold air from north and snow showers develop in the daytime, it is good chances for sun pillar in the evening. This is because the snowing cumulonimbus start losing their power and reduce to stratocumulus with icy virga. And the virga of low and middle level clouds often consists of crystals that make decent pillars.

This is what happened on 1. May in Tampere. Above are some photos from the evening. There was also an attempt of fake sun, but for my criteria it was not quite there yet. These low sun pillars and fake suns are difficult to photograph because of the clipping of red. The fifth image (small thumbnail on the right) is a series of the fake sun attempt: the pillar below the sun in the beginning of the series was blindingly bright, even though I was watching with sun glasses (you need welding glass to observe these properly). In the end of the series the true sun is coming visible. The photos were given lowest white balance value possible and highest recovery value in Photoshop. That's how red clipping was gotten rid of. The downside for this realism is unrealistical blue photos. The leftside photo in the gallery on the second row is the same as the first in the blue series, but with more normal white balance values. There is red clipping that masks the true nature of the pillar / fake sun effect.