A Solution for the C100 Z Finder Pro

I've owned my C100 now since November 2013, and the biggest issue I've had out in the field has been critical focus.  I began trying to solve this issue by placing a Zacuto eyepiece over the teeny tiny viewfinder on the camera with moderate luck.

Zacuto eyepiece over viewfinder.

I was pretty happy with the setup - until I had a big shoot where I didn't have time to mess with checking and rechecking focus over and over.