The bright bursts of fireworks are a quick flash of light that work best with a bit of a longer exposure. The way they paint the sky is very eye-catching, as many of us already know, and giving the camera a bit more time to catch the light helps catch this fast flashes. A steady tripod or something solid to support the camera helps give a crisper image and really makes these streaks and spots of light look that much more defined in the final image. I think when looking at these in black and white, the lines are more defined, and the variations in brightness are much more noticeable, so its good to ensure images are as sharp as they can be on long exposures, as it gives you more latitude if you want to edit them into different forms.
