>>2618822OP: It's not exact science per se, but get yourself a black card to put in front of your lens.
Get an approx exposure at f11 by testing it out before the fireworks starts.
Start the exposure and then just cover the lens with the card after each burst explosion. Count for how long the shutter is open - make sure you don't go past your base exposure.
Usualy you'll land a few different bursts in one exposure. If you're good, you might get the whole fireworks in a few shots.
