There are countless "pocket cinema" cameras on the market, but its near impossible to beat the camera you have with you at all times. Here's a thought exercise: decouple your mind from the notion that what is in your pocket is a sophisticated phone that has other features. Replace the thought with "I have a futuristic camera that can order lunch". See how easy that was? The engineers who design smartphones (now i'm hesitating to even use the word phone here) spend a great deal of time improving the camera and display, whereas the telecom technology in your devices has stayed relatively the same.

There's something inherently gimmicky about a feature length film shot entirely on a phone. The act of shooting on consumer technology should be a means to speed up process. Faster setups, smaller rigs, time is money etc. If the plan is to shoot a long form narrative project one must consider battery life, lens options, and audio input limitations. Despite those limitations, maybe you should still shoot your movie on a "phone". Here's why.

It looks nice.

There's a unique quality to the image itself. It's sharp where it needs to be, and in the right lighting environment it really does look velvety. You can achieve decent background separation just by moving a bit closer to the subject. The minimum focusing distance makes it possible to get incredibly tight shots, and much more quickly than with a conventional video/film set up.

Low light performance? Nope! Your image is going to get mega grainy in low light. The sensor is tiny. The noise almost looks like film grain, especially so in B&W. Luckily you've spent $0 renting a camera rig, so you can splurge on lighting. You will need it.

It's flexible.

Getting macro shots and b-roll in tight spaces (inside the refrigerator, overhead, car scenes) is a breeze. The camera is so small you can really get it anywhere it needs to be. Most of the better capture apps like Filmic and ProMovie have built in stabilization, so a grip/rig isn't necessary. Or you can go crazy on accessories! Gimbals, filters, anamorphic adapters will all add to your production value, while costing much (muuuuch) less than their professional counterparts. 

Workflow, bro.

I would venture to say that even the worst smartphone interface is still superior to the best production camera firmware. You can begin auditioning clips before you ever sit down behind an editing station, quickly flagging the best clips to import. When I work on a 5k iMac, the machine regularly slows down when scrubbing through 4k footage. Not so on my smartphone.

It's good enough.

The resolution exceeds expectations, and the files hold up decently to color correction. Having a fixed lens initially first feels like a limitation, but the ability to toggle between wide and telephoto lenses on the camera covers a decent range of shooting scenarios. Why fight it?

(update: I'm trying to transfer a 35gb clip over airdrop. Maybe not recommended for long interviews)