Focus on street light in the distance
Set Ap to around F5-F10
Lightning brightness Film ISO Aperture
Very close blinding CG lightning (< 100 m/yards) 100 ISO f/16-f/22
Relatively close, blinding CG lightning (~ 1 km) 100 ISO f/11
Distant CG lightning (5-10 km) 100 ISO f/5.6
Distant CC lightning (5-10 km) 100 ISO f/4
Distant CG/CC lightning (10-20 km) 200 ISO f/4-f/5.6
Remote CG/CC lightning (20-50 km) 200 ISO f/2.8
OR use F8 and use the bulb and open it until there is
some lightning and then close it. This is suggested
by doswell and others.
THE LOWER THE F STOP THE MORE LIGHT THAT IS LET IN
SO A HIGH F STOP (F15-20) IS BETTER FOR SUNNY DAYS AND A LOW
F STOP LIKE (F8) IS BETTER AT NIGHT.
Now for Exposure. With ASA 100 film, it is pretty much
f/8 and be there. Oh, f/5.6 will work too, or f/11,
but f/8 sounds about right. The f/stop will make a
difference in how thick any given lightning stroke
appears--at f/5.6, which is letting in twice the
light of f/8, the lightning flash will appear
somewhat thicker and whiter than at f/8.
At f/11, which is letting in half the light
of f/8, the same lightning stroke would
appear somewhat thinner.