15 Impressive Practical Movie Effects That Were Wrongly Mistaken For CGI

2. Oppenheimer's special effects artist, Scott R. Fisher, told Total Film Magazine that the explosion of the atomic bombs was all practical filmmaking. "It's mostly gasoline, propane, any of that kind of stuff, because you get so much bang for your buck. But then we also bring in stuff like aluminum powder and magnesium to really enhance the brightness, and give it a certain look ... We did a bit of that on this, because we really wanted everyone to talk about that flash, that brightness. So we tried to replicate that as much as we could."