On page 216 of the manual it shows accessories for the camera and came across the Angle Finder C. Has anybody tried one of these? I would think this would be crucial for focusing. I here people talking about the Zacuto Z-Finder but it seems like this would work better due to the fact you can angle to your taste.

Thoughts?

Unfortunately, it won't work. The Angle Finder C is an attachment to the optical viewfinder. Keep in mind that an SLR camera has a mirror box to pass the light from the lens to the optical viewfinder. In live view mode (which is how video is recorded), the mirror box is moved out of the way of the sensor, thereby disabling the optical viewfinder.