Alien and Star Wars' art director Roger Christian eventually went on to direct the notorious Battlefield Earth but, long before that, he made his directorial debut with Black Angel. This short film was endorsed by George Lucas who saw it packaged as a short to play before The Empire Strikes Back in Australia and some of Europe, including the UK.
It's the story of a knight from the crusades who gets transported somehow to a fantasy realm – a swords and sorcery John Carter, almost. John Boorman was apparently inspired by the look and style of the film in his approach with Excalibur, and a step-printing device used in the fight scenes was also borrowed for Empire.
While nothing is set just yet, Christian thinks the best way to release the film now will be for download. At just 25 minutes runtime that seems sensible to me too.
Here's the image from the film that Wired have published. Does this jog your memory? My recollections of this film are very, very vague indeed…