In May of 1980, Lucasfilm and 20th Century Fox released the highly anticipated follow-up to one of the biggest movies of all time: The Empire Strikes Back, which built upon the universe established in its predecessor Star Wars and went on to become known as arguably the best sequel ever made.

Today Lucasfilm’s in-house visual effects department Industrial Light & Magic (AKA ILM) hosted a 40th anniversary live-stream event celebrating The Empire Strikes Back with a panel made up of some of the movie’s key behind-the-scenes players: effects illustrator and designer Joe Johnston, stop-motion animator Phil Tippett, effects director of photography Dennis Muren, and chief model maker Lorne Peterson.

Watch ILM Presents: EMPIRE AT 40:

The ninety-minute event began with an energetic and impressive highlight reel showcasing the visual-effects wizardry that went into bringing The Empire Strikes Back to the big screen. Then, in addition to discussing the unique history of ILM and their memories of what it was like working on Episode V in general, the team dropped a number of fascinating behind-the-scenes tidbits about the film’s production, such as:

  • Why the choice was made to create the Tauntaun creatures and Imperial AT-AT walkers using stop-motion animation as opposed to other processes.
  • The challenge of shooting miniature vehicles and ships against lighter backgrounds instead of mostly in the black of space like in the first Star Wars movie.
  • The use of microscopic glass spheres called microballoons to create the snow on the miniature Hoth sets.
  • The decision to have the villainous Imperial walkers come from the right side of the frame during the Battle of Hoth instead of the “good guys,” breaking a long-established Hollywood tradition.
  • How the design of Boba Fett’s ship Slave I was inspired by a hair dryer and a street lamp.
  • The fact that George Lucas recorded temp beeps for R2-D2 before sound designer Ben Burtt replaced them with electronic noises.
  • How the ILM VFX artists would sneak potatoes and tennis shoes into the asteroid field sequence because they found the process so tedious.
  • The reasons why several effects shots were added to The Empire Strikes Back after its 70mm premiere but before its 35mm wide release.
  • The origins of the design for Darth Vader’s Super Star Destroyer Executor.
  • Joe Johnston’s cameo appearance as a Rebel soldier on Hoth in the movie.
  • How ILM almost ran out of time to design and build the Imperial Probe Droid before it was needed.
  • Much, much more.

For more content covering A Galaxy Far, Far Away, be sure to check out Laughing Place’s Star Wars-themed podcast “Who’s the Bossk?”