I'm super ... super particular about the way cameras render motion.
Motion meaning cadence, or how anything in the frame is represented when moving in the final image. Sony has always, to me, been the weakest choice for film-like motion (which sounds silly to even say...). 24P doesn't look like 24P to me, or at least not like Panasonic's 24P, RED's 24P and especially not Alexa's 24P.
With Canon, I resorted to using a 1/45 shutter to fix the issue. I've had friends with similar sensitivities to video motion at twenty-four frames remark that "it looks right, how did you do that?". On the GH2, I use 1/40th shutter and it looks perfect to me.
Nothing that I could figure out on the FS100 would get it to work. And, I took the camera to set, shot b-roll on well lit narrative scenes (a feature film), matched it against Epic shooting the same thing, projected it in a finishing suite at 18 feet (best way to do camera tests for a feature I must say!) and nothing worked. It's just the Sony look.
Is the motion problem related to GOP vs I frame? I take it the external recorder did not help? Is there somthing that can be done in post to help? Does the FS700 have the same problem? Thank you for your time.