The late Henri Cartier-Bresson, whose elegantly effervescent style made him one of the 20th century's most revered photographic masters, famously described what he was after as "the decisive moment."
It was, he wrote, "the simultaneous recognition, in a fraction of a second, of the significance of an event as well as the precise organization of forms which gives that event its proper expression."
Postmodernism, however, has called into question Cartier-Bresson's notion of a single "decisive moment" in which all the elements of a picture come together in a formal and emotional unity. Many contemporary photographers reject the concept entirely, while others seek alternative definitions of it.
German photographer Barbara Probst, for example, whose work is on view at G Fine Art gallery in Washington, has come up with a singularly ingenious riposte to Cartier-Bresson's classic formulation.
Instead of using a single camera to record a unique instant in time, Probst sets up half a dozen cameras equipped with radio-controlled shutters that allow her to simultaneously snap the same scene from multiple points of view.
Because all the cameras record the same subject at precisely the same instant, but from different distances and angles, the resulting series of photographs document not only what the cameras were pointed at but also the act of picture-taking itself.
In one of Probst's series, for example, the artist set up a battery of cameras in her studio so that they all pointed toward her while she lay on the floor. When she tripped the shutters, each camera recorded a different image of her depending on its distance and angle of view.
When the photographs are displayed as a group, one immediately grasps that they all correspond to exactly the same moment in time. Yet in style, mood and content, they could not be more different.
One camera, for instance, recorded only the artist's hand, another captured a close-up of her face and hair, while a third, positioned some distance away, depicts her surrounded by her cameras in the studio.
The fractured nature of photographic reality is further emphasized by the fact that some of the images are printed in color, while others are stark black-and-white.
In another series, Probst photographed her niece gamboling at the edge of a picturesque mountain lake. But she complicated the set-up by inserting a billboard-size photograph of the mountain between her niece and the shore.
One camera, set up at a distance from the shore, records the whole scene -- niece, billboard, mountain and lake. A second camera, set up much closer to Probst's niece, sees just the girl in front of the billboard.
Since the mountain on the billboard looks exactly like the real mountain behind it, however, we can't tell whether the girl in the second picture is standing in front of the billboard or the mountain until we see both photographs displayed together. Only then can we confirm that the mountain in the second picture is not real.
Thus Probst's clever juxtaposition suggests how image and reality are confounded by the process of photography itself.