Will try to catch some fireworks tomorrow evening.
Only film I have is portra 400.
Lightmeter won't do (I think)
So would need to play it by the ear...
And as am not good at that, am looking for advise
Please help![]()
I have a tripod lol
And you guys are serious with such a long exposure....

Surely 3 mins would be far too long for fireworks, it'd just be a complete mess. That long won't be too bad for car lights because everything is uniformed going in the same direction/place. I personally wouldn't go any longer than 10-30 seconds.

Last time I shot fireworks it was about 8 seconds per exposure but you might have to start earlier than the actual firework to get any background details. You won't need to worry so much about the highlights as you would on digital.
A bit late for Lukas but here is some info on reciprocity failure for Portra 160/400 sheet film.I'm hoping you have a tripod?
I don't think that Kodak Portra 400 is amazing in the reciprocity department, so it wouldn't be my first choice for fireworks, but you can overexpose it to death, which is a bonus. Consequently, I'd just do what @joxby said and go EXTRA LARGE with your exposures.
Did I emphasise extra large?
A bit late for Lukas but here is some info on reciprocity failure for Portra 160/400 sheet film.