re: #14 wlewisiii

Huh. Okay. My early experience was pretty humbling with the 7d. I am a rookie at this! Despite a few years experience with consumer video cams. I got good video but I had to lock down everything. I was shooting a video of gold casting, with a torch. Light levels all over the place. The camera does not auto adjust well. So, I’m spinning the aperture wheel. No sweeps no push or pull shots.
I learned nothing happens smoothly. The idea is get a lens that has focus stops and a manual aperture. I hope, rather than a fancy mount so I can smoothly adjust focus on a still camera lens.

What goes awry with the c mount ? Off the focal point a bit?