This is a stack of 12 images of a dill flower.
The first attempt at a stack with a freshly cut flower was an abject failure because the dill wilted between each frame. After placing the cut flower in water, it freshened up, and no longer wilted.
Stacked in Zerene, lightbox with remote flash, D5100 tripod, focus-ring series, 200mm f6.3 1/200 iso 100
The stack was retouched to put an out-of-focus stem back in to reduce its impact.
Thanks, Jon and Randy.
Randy, the steps were made with the focus ring. I start with a frame at one end of the series, usually the part closest to me, then move the focus ring in as small of an increment as I can, looking closely at the junction between the focus ring and the barrel of the lens so that I have visual feedback. The 200mm Nikkor that I use has no slack/play, and moves smoothly, and has a textured surface, which helps judge that the focus has changed. Ideally, a vernier on the lens would give better visual feedback, and I could move in precise increments, but...