turning on 4 1000w flood lights at once with arduino

silasmoeckel wrote

I would expect that 1000w halogen floods will not be completely lit in 500ms as they take a long while to get to temp.

Exactly, dlstilts said he wanted a 0.5s flash. That is why he should experiment with one floodlight to see it it produces the effect he wants. Maybe the halogens will look a bit soft, though I suppose 4kW will be fairly dramatic. Strobes do give a flash.