They are beautiful fireworks, very colorful. I remember taking a lot of fireworks pictures on film over several years. Mostly shot on Velvia, I set the camera to bulb and lens to f8, then just point in the right general direction, squeeze the shutter and hope for the best! A lot were duds but I managed to get some nice shots. Most were hand-held, and with exposures of a few seconds there was "camera shake" due to my pulse, but since the background was just black sky it did not matter and imparted a slight waviness to the fiery streaks which looked quite nice. You obviously used a tripod which was obviously the best choice in your situation - well done!