Photo of the week: January 11, 2013
San Francisco’s weather is notoriously fickle. It can be chilly in mid-summer; warm and foggy; cold and foggy; misty and rainy, all in one day and in any month of the year. When K.P. Tripathi wanted to photograph the Golden Gate Bridge from nearby Marshall Beach, he noted: “…Clouds in the sky were moving so I decided to take a long exposure to smooth it out and give little drama” and he succeeded in providing us with an excellent, Yahoo! Travel Photo of The Week.
Tripathi said he “decided to take a long exposure to smooth it out and give a little drama.” Note the clouds in the upper left of the photo: they’re as smooth as swirling silk. The water looks soft, ethereal and virtually every light on the bridge is reflecting in it…and each light is an eight-pointed star.
Each light is an eight-pointed star because Tripathi set his medium-focal length lens to one of its smallest f-stops, somewhere around f:9 to f:11. At that setting each blade in its aperture scatters just a tiny bit of light and causes Fraunhofer Diffraction…a little eight-pointed star. In his Flickr profile, Tripathi says he uses the Canon EOS D5 Mark III camera, fitted with one of several Canon “L” lenses. That “L” means it’s a top-of-the-line lens, made with the some of the best glass in the world. Because it’s so fine, each of those little “stars” along the bridge is crisp and clear. Tripathi said he wanted a “long exposure,” which required using the smallest f-stop. Had he “opened” the lens to f:4 or f:2.8, there would be no Fraunhofer Diffractions because the blades of the aperture would have been withdrawn, and the photo would have suffered for it.
The photo is pleasing to look at and it’s an excellent demonstration of how, with a digital camera, a tripod and some thoughtful imagination, an ordinary scene can provide an extraordinary photo.