Home    OpticsPOD   What's New    Rays & Shadows   Water Droplets   Rainbows     Not a rainbow!     Primary Bow     Secondary Bow     A's Dark Band     Other Orders     Supernumeraries     Red Bows     Rainbow Wheel     Dew Bow     Sea Spray Bow     Glass Bead Bows     Reflection Bows     Twinned Bows     Cloud Bows     Moon Bows     Image Gallery     Simulators   Ice Halos   High Atmosphere   Links & Resources   Search - Index                   123456789012345678		Alexander's Dark Band
		Photo ©Les Cowley           Dark band. The sky between the primary and secondary bows is noticeably darker than elsewhere. Alexander of Aphrodisias first described the effect in 200 AD and it now carries his name. Light rays undergoing a single reflection in raindrops form the primary rainbow or brighten the sky inside it. Rays reflected twice are deviated to form the secondary bow or brighten the sky outside. Raindrops along lines of sight between the two bows cannot send light to your eye and so the sky is darker there.

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