originally the effect was done with crossfading slide-projectors; now it’s done with an amazing, crisp electroluminiscent [sic] effect
If they’re the images I’m thinking of, the cross-fading projectors were an interim effect - they originally changed only during “lightning flashes” and have returned to that in recent years.
I’m not sure what the “electroluminescent effect” is, though - a back-lit scrim? (As that’s an effect used elsewhere.)
