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21-June-2005, 11:19 PM
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Here are images of a 22° radius sun halo, sundogs, an upper tangent arc, and even a circumzenithal arc (second, combined image) taken from my back garden in Conon Bridge on the longest day, 21 June 2005, at 19:10pm BST (18:10pm UT). The centre of the bow of the circumzenithal arc is always sunwards and red is on the outside.
These high cirrus clouds are cold and contain ice crystals which refract and reflect the sunlight to form the halo and other associated phenomenon. The halo is large and always the same size, no matter where it is in the sky. The images were taken with a Nikon Coolpix 5700, IS0 100, f/5.0, 1/2000sec and 1/500sec, fl=9mm with a 0.45x wide-angle teleconvertor lens and processed with Adobe Photoshop CS, in particular to enhance the contrast. Note that I masked the Sun to ensure the halo and other features weren't washed out by the it's brightness. Eric. 
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21-June-2005, 11:21 PM
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The circumzenithal arc
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22-June-2005, 10:23 PM
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Great catch.
You ought to submit those images to the Astronomy Picture of the Day.
__________________
Heaven's Gate Observatory H47 32° 15' 59"N, 90° 51' 22"W http://www.quantumhyperspace.com/
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04-July-2005, 10:00 PM
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Great shot of the halo reckless. Living in the sub-tropics we don't get to seee a lot of these halo, sundogs etc. When we do see them we dont see a lot together eg sundog no halo, halo no sundog. A few weeks ago we saw a sundog, and partial halo, even the beginning of tangental arcs, but my wife looked straight up and saw this. I had never seen a circumzenithal arc before, and I didn't realise they were so bright. Credit for the photo to my wife, Anne-Louise.
Taken with a Canon ixus 500, don't really know what the setting were as I believe she just pointed and shot (she has a great nack for astrophotography), may have playerd with the exposure a bit.
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