So I just recently got my RED Epic-X, and I've been debating going with the Canon Ti mount over getting a nice PL zoom lens. Can't afford a set of primes just yet, but I'd like to make the step up from Canon glass. I've heard the RED 17-50 doesn't fully cover 5k...is that true? That was definitely the lens I had my eyes on. Can anyone recommend another PL zoom that covers 5k fully?