Depends if you are self videoing or have a dedicated camera person, also depends on how committed to capturing the shot you are. In my early years of video I would forgo the kill shot in order to kill the deer,in the past few years I have passed a number of shot opportunities because the animal was not in the camera frame. As for cutting your chances in half, I would say no, if you're talking about just the camera arm blocking your shot then i would say about 20% of your opportunities are lost because the arm is in the way, but in most cases proper planning of your set up will cut this percentage down even further. I can one think of one time in the past 4 years that the camera arm cost me a shot op.