About ten years ago, while shooting landscapes in the Amazon, David found himself captivated by "the tiniest of living things on the rainforest floor," including the smallest of flowers. Realizing that even the best close-up lenses couldn't get the depth-of-field he could see in these flowers, not to mention the details even the eye often misses, he started experimenting with stack focus photography. What he wanted to capture and share was "a bee's-eye view of nature," and focus stacking was the way to do it.
When he first used the technique, he'd mount his D3X and 60mm Micro NIKKOR lens on a motorized rail device that would move the camera and lens toward his subject at preset intervals. The system did the job: the rail moved the camera and lens, in precise increments, closer and closer to the subject, taking pictures at each interval, with each image capturing a different area of focus.
Today, David uses the D850 because whether you call it stack focus or focus stacking, the capability is built into the camera. (it's also in Nikon's full-frame mirrorless cameras. With the new Z 6 and Z 7 mirrorless cameras, focus shift shooting adds a new feature called “Peaking Stack Images”. This feature, when turned on, will employ focus peaking to create a black-and-white preview stack that can be used to check focus after shooting.) The D850's stack focus feature moves the elements in the lens; the camera itself does not move. The advantages over the rail system are fewer moving parts, fewer settings, less gear to carry when shooting on location and no need for power cords or batteries for the rail.
"The results I get with the D850, considering my concern for the art of the process and the ability to communicate what I see, are equal to the rail system results," David says. In fact, in one respect the results are better because turning lens elements rather than moving a camera reduces or often eliminates a parallax problem the stacking software had to contend with. (Parallax, in photography, is the difference between a subject seen through the lens and the way it’s captured by the sensor. The difference occurs most often as the lens moves closer to the subject.)
Using the D850 means the process of taking the individual pictures that will comprise the composite is pretty much automatic. But it's not push-button automatic—there's equipment to set up, menu selections to make and test shots to take. But in David's view, that's where the creative part of the process comes into play.
If you're interested in creating your own focus stacking photos, or if you've been doing it using the motorized rail system and would like to simplify the process, here's how David gets it done.