Hi Andrea - thanks for the thread. I have a similar situation - newish UMP 4.6 and all Nikon glass. I have started to get a few Canon EF mount lenses - but am wondering if that is a good long term strategy. For now - just three zooms covers me on the UMP, Tokina 11-20, Canon 24-105 F4 and a Canon 70-300 F4-5.6. Anything else I need I can use one of the Nikons with an adapter. The Nikons and Tokina drive me nuts because they zoom the opposite direction from the Canons.
I imagine a LOT of UMP owners are thinking of getting at least one BMPC 4K (I am definitely getting one) as a matched second camera for the Ursa - and so then there is the lens dilemma with that. It's an interesting dilemma because once you start investing in your system, it gets more and more difficult to change it!
The EF solution isn't a bad one in that you can adapt your existent EF system to the BMPC with a speed booster and get all of the functions and the correct angle of view for the lens. You can of course do this with a PL adapter as well:
https://www.bhphotovideo.com/c/product/ ... hirds.htmlfor about $700. Seems to me that if you are making films - and using primes mostly, then PL is the way to go. But if your shooting interviews and podcasts and the like - then EF would be much cheaper and more flexible. I find myself needing the zoom for conferences and interviews.
Now that I am shooting more commercial type promotional pieces - I am starting to look at going with some different glass, and so the PL question keeps rattling around in my head. Another consideration is the availability of rentals in your area. I used the live in Los Angeles and rented all kinds of stuff and had full access to Universal Studios' prop house. These days I am in the boonies and can't rent anything - so if you have access to PL rentals - that would be a good reason to go there. I'm still undecided!