"First footage" refers to the initial recorded video or film that captures a particular event, moment, or scene for the very first time. Full definition
The most recent footage I have on my PS3 is... well, actually, just the very first footage that was ever released. (blog.us.playstation.com)
At E3 last week, Nintendo showed first footage of the next Super Smash Bros., revealing a handful of returning favorites (Mario, Link, Pikachu, Kirby) and three brand - new fighters: Mega Man, Villager from Animal Crossing and the Wii Fit Trainer. (polygon.com)
The boss and I were able to see first footage from LIMITLESS director Neil Burger's adaptation of the Veronica Roth novel DIVERGENT over at Comic Con in July. (thehollywoodnews.com)