Although Marvel's "Avengers: Infinity War" and its untitled sequel are indeed shooting back to back, the ambitious projects are no longer being filmed simultaneously.
Asked about the production schedule, Marvel Studios President Kevin Feige told Collider, “We’re doing them one right after another. … It became too complicated to cross-board them like that, and we found ourselves — again, something would always pay the price. We wanted to be able to focus and shoot one movie and then focus and shoot another movie.”
This news shouldn't come as too much of a surprise. Despite initially being billed as "Avengers: Infinity War -- Parts I and II," it soon became apparent they would be two distinct films. Directors Joe and Anthony Russo confirmed nearly a year ago that the movies would be retitled, with the first part becoming "Avengers: Infinity War" and the second yet to be announced.
Feige confirmed that production of the fourth "Avengers" film will officially begin in August.
Filming is now under way on "Avengers: Infinity War" in Edinburgh, Scotland, and at Pinewood Atlanta Studios in Georgia. Opening May 4, 2018, the film boasts a sprawling ensemble cast that includes Robert Downey Jr., Josh Brolin, Mark Ruffalo, Tom Hiddleston, Chris Evans, Chris Hemsworth, Jeremy Renner, Chris Pratt, Elizabeth Olsen, Sebastian Stan, Benedict Cumberbatch, Paul Bettany, Samuel L. Jackson, Cobie Smulders, Benedict Wong, Zoe Saldana, Karen Gillan, Vin Diesel, Dave Bautista, Pom Klementieff, Scarlett Johansson, Tom Holland and Anthony Mackie.
The untitled sequel follows May 3, 2019.