Monday, December 8, 2008
PHOTOGRAPHER'S DIARY: I've been working with high dynamic range processing (HDR) for almost a week. HDR isn't new, but it's new for me, and it is changing the way I look and see as a photographer. Whether HDR leads to more literal representation of what I see is my personal choice, but it does permit greater fidelity between the world seen and the world photographed.
I shot this image on Friday. Last Sunday I would have passed it by. There are more than 8 stops of information in this image from the darkest pixels to the lightest, far more than film or digital cameras can record in one image. (Five clean stops of light is about the best one can expect from current DSLRs. After that the top starts losing saturation and the bottom gets noisy.) As one brightens this exposure, the sky loses all detail long before the foreground tree gets any. Nor is it just that detail is lost. Even in situations where the dynamic range is less extreme, over-exposed sky quickly bleeds into dark areas. This would spoil the crisp texture of branches in this shot.
To make this image I shot multiple images at shutter speeds ranging from 1/20th of a second to 1/5000th of a second. My goal was shots that encompassed the darkest and lightest tones and filled out a fair sampling of the middle. The software suggests shooting two stops above and two stops below the correct exposure. In fact, this picture required more to encompass the intensity of the setting sun. I checked the trailing lines at both ends of the histogram until I saw they had ended in all three primary colors.
I've found orchards, unless on or surrounded by some pretty steep hills, to be especially difficult to shoot. I photographed in the neighboring peach orchard through much of the fall. The grotesque contortions of the branches, the trees' neat rows, the foliage, fruit and flower all appeal to my photographic tastes, and, except when the winter wind blows, they are beautiful places to walk. At the orchards on the top of Baldwin Hill especially, the dance of the fruit trees wants to whirl in partnership with the sky, and often the best skies lie close to the sun. Until this week, I looked at such scenes with the knowledge that my image would be mostly silhouette. Knowing I can put detail into the shadows lets my camera enter new worlds.