Expand your range, both optically and otherwise
January 7, 2009
HDRI (High Dynamic Range Imaging) has become a much-discussed way to get the produce images with a range of tones and colors similar to what the human eye sees. Here are some basic HDRI techniques and advice.
You can capture High Dynamic Range images with any lens--telephoto, macro, or even a locking Lensbaby like the new Composer model. But by far, ultrawide angle lenses--both rectilinear and full-frame fisheyes--are the easiest to get started with for a number of reasons.
Both these lenses take in broad, sweeping angles of view. The big difference is that full-frame fisheyes don’t attempt to keep straight lines straight. Straight lines at the edge of the frame are dramatically bowed with full-frame fisheyes.
But with either flavor of full-frame ultrawide lens, close focusing is usually within a few inches of the lens to really showcase foreground elements. You can achieve great depth of field, even at medium apertures.
Because of the expansive angle of view, you’ve got to be aware of keystoning (or the vanishing point effect) in regard to straight-line elements in the frame. Make sure that one of the axes of a geometric, ultrawide composition is plumb with the sensor plane. For example, when shooting up at a building, make sure the top and bottom windowsills are parallel with the top and bottom of the sensor.