Page "Star Trek IV: The Voyage Home" Paragraph 39

The Bird-of-Prey's travel through time was one of the most difficult effects sequences of the film.

While ILM was experienced in creating the streaking warp effect they used for previous films, the sequence required the camera to trail a sustained warp effect as the Bird-of-Prey rounded the sun.

Matching the effect to the model was accomplished through trial-and-error guesswork.

The team did not have the time to wait for the animation department to create the sun for this shot.

Assistant cameraman Pete Kozachic devised a way of creating the sun on-stage.

He placed two sheets of textured plexiglass next to each other and backlit them with a powerful yellow light.

The rig was rotated on a circular track and the sheet in front created a moire pattern as its position shifted.

Animator John Knoll added solar flare effects to complete the look ; Dow recalled that the effect came close to matching footage of the sun taken by the Jet Propulsion Laboratory.