wheeldeal said:
An imperial officer's transmission is lost as a result of an asteroid impact. I hadn't seen this effect before, although I've heard it was included on certain laserdisc releases. I wouldn't be surprised if it was present in the 70 mm 1980 version, but it's not part of any original 35 mm release I've seen.
This has always been there.
The reason you may not be familiar with it was because the hologram of the Imperial officer who dies (he's on the bridge of the Star Destroyer you see get smashed by an asteroid in the establishing exterior shot) has traditionally been panned-and-scanned out of the image when transferred to television to focus on Vader, who is on the opposite side of the shot.
It has always been visible on all anamorphic and 70mm prints and letterboxed video editions.