So, I finally managed to go to a 4th of July fireworks show, unlike other years when I was stranded at home with my youngest refusing to go because of her being scared of loud noises. She loved the show and so did I. In fact the setting was perfect to try out some new fireworks photography techniques I’ve read about online and I was ready to put it to the test.

WHEN STARS COLLIDE
The trick is to refocus on a long exposure value (1-2 seconds). Meaning that as soon as you near the boom (or see the explosion), you hit that shutter release button and refocus. Refocus to where? That will depend on your lens. I had a 50mm f/1.8 lens on my Nikon D7100 that did the trick perfectly fine by refocusing to infinity and [literally] a little beyond. That added that little blob at the end of each firework stem.
The results were these very bizarre looking 3D blobs and shapes, with tentacles looking almost like a deep sea creature.
The reverse technique (start on focus and end defocused) produces as interesting results as the first one, but you have to manually know where your focus ring should be (usually on infinity). I used my thumb to hold the focus ring at 12 o’clock, so after each shot I refocused using that reference.
Ah, and make sure you have your camera on a tripod. It helps having your hands free to hit the shutter release and turn the focus ring.
A wide aperture helps, since it will add dimension to the light streaks. Set your ISO to 100 for minimal noise.