Could anyone please let me know what sort of settings would be best on which camera and which lens, as we are scheduled for more lightning tonight.
Huge thanks in advance,
Well, for starter, the lens to use depends mostly of your view on the lightning storm.
If you're, say, on a hill with the heart of the storm a few dozens kilometers away, use the 70-200.
If you're in or close to the heart of the storm, the 24-70 should be better suited.
Next, find a place that's not under the rain and if possible not too exposed to the winds. (yeah, not that easy in a storm, I know... I find that the back of a car, with the hatchback open, is fine (mostly) if there's nothing better nearby)
Now, concerning the parameters to use : First, manual focus to a building/landmark/etc... near the place where the lightnings strike.
Next, put your camera to 100 iso, f/5.6 to f/8 and 5 to 10s exposure (this depends on the ambient light. In a city, 5s is plenty enough. In the country, 10s may be a bit too little. The goal is that your picture should be very dark if there are no lightnings on it. You're counting on the lightnings to provide light (think of them as big deported cobra flashes.
Then fire up the magic lantern intervallometer (or do it through the EOS utility, or manually at worst), and go for 10 pics at a time.
Most of those, there will probably be nothing to see. But on some of them there will be one, two or more lightnings lighting the sky and the landscape.
Good luck !