Something I saw on TFN and was motivated to post here:

As JW Rinzler’s Making of ROTJ book attests, the infamous deleted scene where Luke assembles his new lightsaber while Vader calls out to him with the Force was cobbled together in post-production, with Mark Hamill filmed standing in front of a bare-bones set and the footage of Vader being recycled from ESB.

But the latter footage has something unusual: it’s step-printed, with frames being duplicated to create a “dream-like” effect.

IIRC Irvin Kershner only used step-printing once in ESB: during the cave scene on Dagobah, where Luke confronts the vision of himself in Vader’s mask.

So where does the footage of Vader in his meditation chamber with step-printing come from?