Could also be the projector. Or how the projector is set up relative to the camera. Even very small vibrations can cause perceptible jitter. You could try sand bagging the projector. And you might need quite a few sand bags. I had to use a lot of sandbags for a 16mm projector once - and Super8 projectors can be a lot worse. In one situation the vibration of the projector went through the table across the floor and up the tripod.
The interesting thing is that when watching a film live your brain can adapt to the small vibrations and cancel them out - but a video camera doesn't have such a brain and will burn such into the video. One could argue that your brain should be able to cancel out the jitter transferred to the video - and it can to some extent - it helps if you turn off the lights and watch the film full screen so that one minimise any external frame of reference. Of course, once you are alert to it you just can't stop noticing it.
Sandbags then. They do help a lot.
Edited by Carl Looper, 04 April 2016 - 01:11 AM.