I tried this earlier in the summer using (expired) 50 ISO film. I had read elsewhere that approx. 30-second exposures were good, so I tried that, with a 28mm lens (35mm film).
2 points:
- 30 seconds is way too long. As mentioned above, you end up with the initial shell burst and the trail - the shell burst can overpower everything else and just doesn't look that good. Other people I was out with were shooting digital, and using 2-4 seconds (100 ISO) after the shell burst, and had decent results.
- from where I was the 28mm lens was way too wide. Depends on where you are relative to the fireworks - I could have used an 85mm or longer and had nicely framed shots
Next time, I'm going to use 2-4 second individual bursts, or use an older camera that has no double-exposure lock so I can shoot multiple exposures after the shell bursts (or the hat method as above, but I just don't trust myself to not knock my lens