[7] One of Jein's first jobs was building models for the sex comedy spoof Flesh Gordon; this was followed by work on a number of television series, commercials and movies including Wonder Woman and The UFO Incident.
[8] In 1975 he was contacted by Douglas Trumbull's office and asked to do some work on Steven Spielberg's Close Encounters of the Third Kind.
[8] For that film Jein contributed a number of models including miniature landscapes for UFOs to fly over, but most significantly he and his crew built the detailed mothership model that features heavily in the final sequence of the film after Spielberg decided he wanted "a more flamboyant design".
[8] For their work Jein, Trumbull, Roy Arbogast, Matthew Yuricich, and Richard Yuricich were nominated for an Academy Award for Best Visual Effects at the 50th Academy Awards, but lost to the team who produced the effects for Star Wars.
[11] In 1986 he and a team at Industrial Light & Magic built the original six-foot model of the USS Enterprise (NCC-1701-D) designed by Andrew Probert for the pilot of Star Trek: The Next Generation.