How-To
Text And Photography By Craig Blacklock
Finished Image. Craig Blacklock defied the limits of depth of field and diffraction to create this image. He created the series of exposures shown here and on the next page, shooting each one for maximum sharpness in a limited area and then composited the final image together.
For the first time since the invention of the medium, photographers are now able to create images that rival our visual memory. For years, we’ve been using high dynamic range (HDR) techniques, combining bracketed captures to extend the range of exposure. Using the stacked focus technique, we can extend depth of field, as well.
When we view a composition, our eyes scan the scene, refocusing on every detail, then our brain composites everything we’ve seen into a visual memory with the entire scene sharp. Painters have depicted the world this way for years, but prior to the advent of stacked focus, photographers were limited to what a lens could resolve in a single capture.
The stacked focus technique allows us to overcome this limitation by making multiple captures, each at a slightly different focus distance, then use software that selects the sharpest pixels from this stack of captures to extend the depth of field through the entire photograph or a specific range within the photograph. In addition to extending the depth of field, the sharpness is enhanced, because each capture creates another focus plane that is in true focus