I have a question relating to this issue. I just had my R16 serviced for a shoot this weekend, and it ran a couple test reels really well. I remember, though, that when I loaded the reels, the loop stayed very steady in place when running; the 'shape' was very consistent and steady. During the shoot, the loop somehow got tightened, because when I opened the camera, thinking I was at the end of a roll, the last couple feet were still left, and I noticed that the top loop was nearly horizontal coming out of the top spool as it entered the gate, which I know is a bad thing.
Now, I noticed before this happened, and definitely every time I load now, the loop will keep its shape generally, but it isn't as rock steady as when I first brought it home. In 2 fps, the loop appears to raise up a hair, then comes down as it's being pulled by the claw, then back up, down, so that at 24 fps, it appears shakey (is the best word I can think of), and not as rock steady as before. When I look at the film's sprocket hole as it enters the gate, it looks steady when running film, but that's hard to detect with the naked eye. Is my footage going to be jittery? Does the loop have to be totally steady in shape, or is a little 'play' allowable? I'm having nightmares that the footage from the shoot is going to come back jittery, from the moment I noticed the tightened loop on... I'll be running a test reel this week to confirm, but just hoped I could get some info from someone here...