I'm currently use a canon 70-200 f4 with my iscorama 54 on my 5d mark II and it fits perfectly and allows me to zoom with the canon and focus with the isco.  I'm thinking about buying a BMCC and an not sure how to mirror this setup on that camera. I did look at the panasonic 35-100 f2.8 but its kinda pricey.   Also what is the widest lens that I can use on the BMCC with a iscorama 54? 28mm?     Any other suggestions?      Thanks Greg