How to photograph fireworks

Taking nice pictures of fireworks is easier than you think. The only difficulty is that you need some equipment. Here's a list of what you'll need:

1) a sturdy tripod
2) a cable release (so you don't induce shake by touching the camera)
3) a DSLR capable of having mirror lockup function (not essential, see below)
4) a nice position overlooking the fireworks
5) patience for trial & error

Probably the most important point is getting to your location early, so that you can install yourself in a good spot. If it's already dark, it's a good idea to take a flashlight with you, as not all cameras have back-light LCDs (mine doesn't).
Ideally you want a high point, with not only sky included, as that quickly becomes boring. If you are able to find a spot with reflections on a lake and recognizable buildings, that's ideal. For the example pictures below, I was much too far to get any lake reflections, but you can clearly recognize Geneva's cathedral.

Set up your tripod, and frame the shot. Be sure to leave enough free space for the fireworks in your composition (and check this again when they have started).

Set the camera on manual focus, as it will not be able to auto-focus in the dark. In my case, I set focus on infinity, as I was very far away. I used a Canon 450D, with a 70-200 lens set at 200mm and a 1.4x multiplier. The final equivalent focal length in full frame format(adding the 1.5x crop factor of the 450D) is 420mm.

If your lens has image stabilization (IS in Canon speak, or VR in Nikon speak), turn it off. Since you're already on a tripod, there is no need for further stabilization.
If you have any filters on your lens, take them off. I have noticed that when I left my UV filter on, I got strange green ghosts in the image. Nothing irremovable in post, but a pain nevertheless.

For these pictures I used the following settings: ISO 100 (the minimum), f/8.0, and bulb mode. You want to control all three settings manually, so find out how to do that in your user manual.

Bulb mode means that your camera will stay open the time you depress the remote cable release.

Before shooting, you will also need to put your camera in mirror lockup mode. In the case of the Canon 450D, this is a custom function, so it's not easily accessible. If you don't find it, fear not. It's not totally essential, but it ensures less camera shake. Mirror lockup tells the camera to put up the mirror, before you open the shutter. This minimizes any vibrations inside the camera.

So once you've set manual focus, manual ISO, manual aperture (anything between f/5.6 - f/11 should do), and manual time (bulb mode), you're ready to shoot!

If you're using mirror lockup, remember that the first time you depress the shutter on the cable release, it will just instruct the camera to put the mirror up. You then need to depress the shutter again, and leave it down for the exposure time you want. I typically shot between 4 and 7 seconds. Here you need to experiment. You need to visualize where the fireworks are exploding. If they explode at multiple places, then the exposure should be shorter. You need to judge the amount of light that comes onto the sensor. If the fireworks pop slowly, you can leave the shutter open longer. If you're shooting the finale, then it must be shorter. Check your LCD after a couple of shots and you'll get the hang of it.

In the end, it's more luck than science. Sometimes you can shoot a nice sequence with difference types of fireworks at different heights. Other times, the picture will just be a huge mess, with too much clutter.

In any case, don't hesitate to shoot a lot of frames and shoot quickly (at the start of the show). You never know how much wind and smoke there will be after a couple of minutes of fireworks.

And lastly, when you pack up, be sure to check you haven't forgotten anything before you leave!

That's it for me. Let me know in the comments if you have any other tips & tricks.