• Balthazar@lemmy.world
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    5 个月前

    I’m guessing this is due to the steam coming out the vent rather than a fine layer of ice crystals across the entire sky. The sundog is only visible with that particular geometry of the sun and the vent, right?

    • Troy@lemmy.caOP
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      5 个月前

      Sundog is on both sides, just using the steam to tone down the brightness of the sun for higher dynamic range, to allow the colours of the sundog to photograph better.

      It’s not really steam either – it’s a sign of really cold air causing the natural gas furnace exhaust to condense rapidly. The exhaust wouldn’t normally be visible.

      It’s quite cold here. Currently -20°C on the ground and certainly much colder as you go upwards.

    • ch00f@lemmy.world
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      5 个月前

      Rainbows due to water moisture show up when you face away from the sun. The geometry doesn’t work for when you’re facing the sun.

        • ch00f@lemmy.world
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          5 个月前

          Right. Sorry, I thought you were implying that the liquid moisture in the steam was causing the sundog. Didn’t realize it was cold enough for steam to freeze.