Volcanic eruptions and brilliant sunsets go hand-in-hand. The eruption of Mount Krakatoa in 1883 reportedly produced beautiful sunsets all around the world for over a year.
So what about the recent eruption of Popocatepetl near Mexico City?
"When Mt. St. Helens blew, we received a lot of photos from students who had taken pictures of the dramatic sunsets produced by the eruption," said Chuck DeLaney, Dean of the New York Institute of Photography."I doubt we'll be seeing many as a result of this explosion."
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| ©NYI Graduate Lukas Forejt |
Indeed, despite some reports from Florida of a few exceptionally photogenic sunsets, the atmospheric effects of the explosion as least as far as sunsets go seem minimal. Why? What's the connection between brilliant sunsets and volcanoes? To get to the bottom of this, NYI talked to Dr. Craig Bohren, Professor Emeritus of Meteorology at Penn State University, who explained that, despite conventional wisdom, the ash from the eruption has very little to do with it.
"A volcano sends a lot of sulphates into the stratosphere," explained Bohren, „and these sulphates undergo chemical reactions to produce really small particles, which will give us the blood-red sunsets."
Bohren explained that ash particles simply aren't small enough to produce the scattering filter affect of the sulphates. The ash, in fact, just acts like a neutral density filter by reducing the brightness of the sun.
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| ©NYI Student Armando B. Frasco |
As it turns out, the Popocatepetl eruption wasn't powerful enough to pump the kind of sulphates into the stratosphere that we would need for really amazing sunsets here in the States or elsewhere. But no matter. Whether you're in position to photograph a volcano-enhanced sunset, or if you're just wanting to take a picture of an "ordinary" one, NYI offers a series of tips this month for photographers interested in capturing that colorful moment.
"One of the first things we remind photographers to do in this situation and in many others where exposure may be tricky is to bracket their images," said DeLaney. "This way the photographer is sure to come away with at least one correct exposure in each series of shots."
To read more about the science behind sunsets and for tips on how to photograph them effectively see the Breaking News article on the Popocatepetl eruption on the January Web site of the New York Institute of Photography at http://www.nyip.com
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