The online horror community was buzzing last Halloween when BloodyDisgusting.com released footage from an old film reel which contained never-before-seen tests from The Exorcist. It showed crew testing Linda Blair's convulsions and levitation, her bed shaking and other on-set special effects within Regan's bedroom.
At the time it was speculated a man seen in most shots, sporting a dashing 70s moustache and blue collard shirt, might be Writer-Producer William Peter Blatty. Despite the man sharing a resemblance with the author, I was sceptical (as were others in the discussion forums), as the producer is not usually seen mixing it up on set at this pre-production stage, especially on a big studio film. Curious, I sent an email to the First Assistant Director, Terrence Donnelly, asking if he could recognise anyone pictured. He kindly replied and confirmed my suspicions– it was not William Peter Blatty in that footage– it was Terry himself!
The mystery is solved! The guy in the reddish shirt in that clip is my 2nd AD, Alan Green, and the blueish shirt dude is yours truly. I had totally forgotten about those early days of pre-production when we were working with the SPFX team to make sure that everything was working to Billy's satisfaction.
Terry also confirms the footage was shot on 35mm and reduced to 16mm when duplicated.
Although the quality of those clips is pretty grainy I don't remember using 16mm for those tests…they are probably just dupes of dupes of dupes of the original 35mm negative.
You can watch all of the test footage below, and see a recent interview with Terry here, filmed in 2012.