I posted this young lady in a past blog. At an Orlando pool party, I had photographed her earlier.
Later on in the evening, women started spinning LED poi sticks.
Some DSLRs contain two flash curtains. When set on the first curtain, the flash starts at the beginning of exposure. On the second curtain, the flash starts at the end of exposure.
To photograph the cool LED trail, I set the camera on the second curtain. Also, I slowed the exposure to one second. The ISO was 800. The aperture was f/5.6.