Shooting fireworks is easy if you follow some basic steps.
Step 1. Know your camera. Every year, I see people fumbling with their cameras in the dark, trying to make adjustments and navigate their camera settings . Trying to change settings on your camera in the dark can lead to frustration and lots of missed opportunities. Be sure and spend some quality time with your cameras manual before the big event, be sure and get comfortable setting your cameras Mode, ISO, Shutter, and Aperture settings. Also, it's a good idea to bring along a mini flashlight to help lumen-ate things when needed.
Step 2. Bring a tripod. This is essential. shooting in the dark requires long exposures, sometimes several seconds. Trying to hand-hold your camera for that length of time is next to impossible. Also, if you want the best control over the quality of your shots, I recommend a shutter release cable. A cable release ensures stability, and makes taking pictures a much more comfortable process, since you can watch the fireworks in the sky, and time your shots much more accurately.
Step 3. Pick a good vantage point to shoot from. Location, location, location. Arrive early and scout a good location with an unobstructed view. Be sure and stay clear of ambient light sources (such as light poles) that will cause your shots to overexpose. Additionally, be sure and pay attention to the wind direction. Fireworks emit a tremendous amount of smoke, thus ruining your next shot. Try and position yourself upwind, so the smoke is going away from you.
Step 4. Turn Autofocus off. You heard me right, turn it off. Most cameras have a terrible time with low-light shooting. Low-light shooting can cause cameras autofocus system to constantly hunt in the dark. Autofocus is simply not needed for fireworks. Simply set your lens to infinity.
Step 5. Camera Settings. The settings I give you here are starting points. Once on location, you will no doubt have to make slight adjustments, but for the most part they are a good place to start.
Set your camera mode to Manual Mode.
Set you ISO to 100.
Set your shutter speed to BULB.
Set your Aperture to f/11
Step 6. Exposure Timing.A good rule of thumb is to open the shutter as soon as you hear or see the rocket shooting into the sky and to leave it open until the burst is dissipating. This will usually take several seconds. Anywhere between 1 and 4 seconds, usually give excellent results.