Re: F3 and Epic low-light/dynamic-range, how do they compare?
 

24-105mm is not the best choice lens for low light shooting even with DSLRs, and they are much better in low light than RED cameras, but if you can rent f 1.4 lenses and have couple small lights, any lights, for the job you'll be way better off with Epic,
I loved my Z1U, but today high end consumer camcorders have better picture.

Re: F3 and Epic low-light/dynamic-range, how do they compare?
 

The FX-1 has easily been eclipsed by the Epic, but you would be hampering the Epic by using the 24-105 because it's a stop slower (F4) than the zooms one would usually use on a large sensor camera (which would be f2.8). That's essentially turning a ISO800 camera into a ISO400 camera...and the FX1 is like ISO 320 or 200.

Do yourself a favor and beg/borrow a Canon 24-70 F2.8 lens for the Epic and you'll be golden. You'll find shooting at ISO1600 on the Epic with a 2.8 lens will let you shoot in many, many places while using very small lights.

Re: F3 and Epic low-light/dynamic-range, how do they compare?
 

Dirty little secret of the Canon 24-105 is that while technically an f4 lens there is an enormous amount of light lost inside the glass and the effective Tstop (actual light transmission) is closer to 5.6 - i.e its very slow.

Re: F3 and Epic low-light/dynamic-range, how do they compare?
 

Wow, thanks so much guys. That's great advice. I'm pricing rentals for the upgraded Canon lens now.