Nice clip. I've been looking into this lens. Do you think you're really getting 180 degrees on the diagonal? It's a little hard to tell from your footage.
The 6.5 Opteka is a Pentax mount lens that is 180° with a APS-C sensor so it is less with the m4/3rds sensor on the GH1/GH2. Here it is on my Pentax K-7:
