Well, 483 shots today, and I got my plane of focus issues mostly solved, but I ran into another problem: somehow, 1/32nd is suddenly not fast enough to freeze drops. That, or diffraction kicks in earlier than expected on the Vivitar, or ISO400 has some blurring effect on objects in motion.
According to the SB-700 manual, a 1/32nd power pop should last for roughly 1/18182 second. For the record, everything I’ve read suggests 1/8000th to freeze droplets, and I’ve fairly successfully captured droplets at 1/32nd. So I don’t think that could be it.
So I’m leaning toward the diffraction answer or the ISO answer, though more testing will be required (unless someone has the answer).
Thing is, the splashes were mostly sharp, and the ripples were all sharp, as long as they were inside the rather wide focal plane.
So maybe diffraction isn’t the answer, unless faster moving objects are subject to greater effects from diffraction than slower moving objects.
Again, more testing and more research will be required, in addition to more attempts.
But not tonight: I’m wiped out.
D7000. Vivitar 70-210mm f/3.5 Series 1 (Kiron). ISO400, 1/250th, f/11. SB-700, zoomed to 70mm, at 1/32nd, fired behind and across the scene. Cropped to roughly 1/4 size, and subjected to ~5 or 6 minutes of slider play, but only after ~an hour of choosing which of the 483 failures to submit…