How did ILM create the hyperspace tunnel effect? In Star Wars: A New Hope, right before the Millennium Falcon exits hyperspace, we see a "tunnel" through which the ship is traveling:



How did ILM create this effect in 1976?



NOTE: I am not referring to the "stretching star lines" effect shown when a ship enters or exits hyperspace as detailed by John Dykstra in a 1978 interview with the Fantasy Film Journal. I am specifically referring to the blue tunnel effect seen while the ship is still in hyperspace.
Although it looks like a slit-scan effect similar to the Tom Baker era Dr. Who titles, in this case, the effect was very simply made with mylar - a reflective plastic.  Due to time and budget constraints, there wasn't much they could do, so they made a tunnel out of mylar and flew the camera through it.  They apparently had a lot of mylar left from making the reflective background behind the starfield.