Multibows at Niagara

Niagara's falls are famed for their bows from sunlight playing on the mist and spray.    These, perhaps unique, shots by Michiel de Boer show quite another aspect – multiple rainbow segments at night.   Each has an inner primary and an outer reversed colour secondary. All is not what instinct tells us – Read on!

©Michiel de Boer, shown with permission.
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The American Falls in the picture are lit by powerful floodlights blasting across the Niagara River from the Canadian side.  

“I was walking down by the falls [on the Canadian side]. That night the wind blew the mist from the Canadian Falls - to the right and not in the picture - in front of the floodlights lighting the American Falls.   As I walked by I suddenly saw a beautiful rainbow in the black air. 

Because the floodlights are in a row, multiple unaligned rainbow fragments appeared. Nobody seemed to care too much but I was rather amazed.”

 

 

Instinct tells us that the light beams are radiating outwards from a point near the base of the US Falls.    In that case the bows would be the much sought 3rd and 4th order rainbows!    Not so.

Each rainbow segment is from an individual floodlight behind the camera on the Canadian side.   The segments narrow towards each individual ‘anti-lamp point’, the equivalent of the daytime antisolar point and the centre of rainbows. 

The bows are diffuse with unsaturated colours because (1) the lamp beams are not as parallel as sunlight and (2) the mist droplets are small giving tendencies towards fogbows.






The floodlights. These ones beam towards the Canadian Falls, the ones directed at the US Falls that created the pictured bows can be seen faintly in the background.

Smaller lamps, and car headlamps (not when driving!), can be used to generate outstanding ice halos, fogbows and glories.