I saw this again earlier today…
A really absorbing and insightful documentary (from 2015) - featuring Dave himself, and interviews with Star Wars producers Gary Kurtz & Robert Watts, actors Kenny Baker & Jeremy Bulloch, along with archive footage of Ben Burrt & James Earl Jones, and many people behind the scenes involved the making of the OT films and the look and design of Vader.
It features some stunning artwork depicting famous scenes and images from throughout the Original Trilogy.
The doc also touches on his early life, his long career in film and tv before and after the Original Trilogy films, as well as his life since.
As the story goes in regards to Dave Prowse supposedly revealing the end of the Original Trilogy to the press before filming had finished… this is debunked here. Also there is story from the journalists who broke the leaked story at the time - in which they claim it was NOT David Prowse who was the source providing the leaks to them.
Yet still Lucasfilm persist with shunning the actor, making him persona non grata from attending official functions etc, and also from the larger conventions - which the doc also covers.
Well worth a watch - and with some top narration from Colm Meaney.