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February 26, 2012

THE STORM BEGINS


... this is one of my first experiments in high-dynamic-range multiple-image photography ... with the brightness of the parking lot lamps and the darkness of the shadows and the distant trees, it was impossible for my camera's image sensor to capture the extreme variance between the high and low light levels in this scene ... this is known as "dynamic range" ... imagine a foggy, muted landscape, with no shadows, everything grayish ... that's "low dynamic range" ... imagine a brightly lit snowscape, with glaring reflections and extremely dark shadows, that's a "high dynamic range" ... our eyes deal with the latter by constantly darting around, from dark to light and back to dark again, adjusting constantly so that we can perceive everything ... in a sense, we take "multiple images" of the scene, but we do it so fast, and our brains integrate the images so seamlessly, that we're unaware of the process ... for high dynamic range scenes, what our vision handles with relative ease neither film nor digital sensor can do with a single glance ... so, the trick with hdr photography is to take several pictures, each exposed for a specific light value ... here, i took five images in rapid succession ... in the first the picture was almost totally black, but the lamps were correctly exposed ... in the last the picture was almost all white, but the details showed clearly in the dark areas ... i then used a special program, photomatix pro, to combine them and make all sorts of adjustments so that the final image was as i desired ... HDR, including its extreme manifestations, can evoke seriously negative emotional responses from some photographers ... i used to hear the same diatribes concerning "black & white vs. color," "large-format film vs. 35mm," "kodachrome vs. fujichrome," and, of of late, "film vs. digital" ... all foolishness, as far as i see it ... seeing the world, trying to share your vision, that's all that counts ...

NIKON D200-SIGMA 10-20MM@14MM-F8-2 SEC TO 1/8TH--ISO 800


... p.s. ... so you'll understand that my "foolishness" comment is factually based, examine this image:



"The idea of using several exposures to fix a too-extreme range of luminance was pioneered as early as the 1850s by Gustave Le Gray to render seascapes showing both the sky and the sea.  Such rendering was impossible at the time using standard techniques, the luminosity range [ed. note: "dynamic range"] being too extreme.  Le Gray used one negative for the sky, and another one with a longer exposure for the sea, and combined the two in a single picture in positive."  http://en.wikipedia.org/wiki/High_dynamic_range_imaging

"Most photographers found it impossible to achieve proper exposure for both landscape and sky in a single picture.  this usually meant sacrificing the sky, which was then over-exposed.  Le Gray's innovation was to print some of the seascapes from two separate negatives - one exposed for the sea, the  other for the sky - on a single sheet of paper."  http://www.vam.ac.uk/content/articles/s/gustave-le-grey-exhibition/