Last week Morningside College canceled their fireworks because of rain and rescheduled for tonight. I saw a technique of pulling the focus during a time exposure. Sounded easy on paper, but was much harder than I expected.
The photos were shot with a short time exposure at the lowest ISO possible (ISO 64 on my camera.) I read that wider apertures work best, I wanted to shoot at f/2.8, but it was too bright out. The fireworks display started early, at 9:30, before it was completely dark out, so I shot mostly at f/6.3.
I started with the lens out of focus when I opened the shutter and quickly turned it into focus during the exposure, closing the shutter quickly when in focus. And focusing was a crap shoot since it was done during the exposure.
It was a short fireworks display. I think this technique would work better if A) it was darker out when the display started. B) It was a longer display so I could experiment more. And C) If there would have been more solo bursts. Most of the bursts at this display were in rapid succession, which normally would be good for shooting photos, and great for the spectators. But it did make this shoot more challenging.
This was my first try with this technique, and I look forward to trying it again in the future.