Replay: There is always a frisson of excitement generated by big chip cameras, but that doesn’t mean they are always the best answer to the job in hand.
Recently I was faced with a decision on a small, independent shoot: is it better to take out an ENG-style camera, with its smaller, easier-to-focus sensor, or one of the world's many current cameras aimed precisely at that sort of shoot, with a 35mm-sized chip behind the lens? Eventually, I went with Sony's FS700, convinced that the short depth of field was a plus, not a minus, and that the enhanced dynamic range of comparatively big photosites (notwithstanding the FS700's 4K native resolution) was worth the hassle.
Excited as everyone gets about big chips, looking back I'm not sure that was the right choice. I'm sure that the crew will not feel hard done by if I mention that there weren't enough of us, nobody was assigned as a full-time focus puller, and the small lighting package of a low-budget show rarely allowed for anything other than the widest possible aperture. And that's before we even consider the sheer timing issues: to give even a top-gun focus puller a fair chance, focus marks need to be laid out and measured, and sufficient rehearsal needs to be available such that actors, dolly grips and camera crew can all hit them with precision.
If you're the next Bond movie, that's all a given: everyone has a very specific job, plus the time and equipment to do it to the highest possible levels. If you're a pocket-money shoot trying to cover twelve pages of complex action and dialogue in three days over five locations with minimal crew, then life becomes a little more — well, let's be positive about this — concentrating to the mind.
Small chip alternatives
The alternative, which I wish I'd taken, would be some sort of 2/3” camera, something like an older Sony HDCAM, such as the F750 or F900, with a recorder from a company such as Atomos or Convergent Design to avoid being locked into an expensive and increasingly dated classic-HDCAM workflow. Other options exist, although venerable (by modern standards) cameras like Viper are starting to look a bit long in the tooth from a sensitivity standpoint. If you can still find an F23 for rent, they're great cameras, as are many of the current types used for ENG if set up correctly.
All of these possibilities would provide smaller chips, with easier focussing and a huge selection of zoom lenses available. If you want to push the boat out a bit and go for more movie-oriented glass, there are a few comparatively rare sets of Zeiss DigiPrimes out there, as well as various options for putting PL mount glass on B4 (that is, 2/3”-oriented) lens mounts. Those options are likely to be more expensive, though, and I suspect that many people who choose to shoot 2/3” cameras for drama will do so on ENG-style zooms. They do, at least, tend to have lens motor gearing built in, although follow focus packages (whether mechanical or radio remote) may require different output gearing to suit B4 lenses as opposed to the PL types with which they're more usually used, which typically use a different pitch.