I was recommended to check out the Atomos UltraSync Blue for a way to synchronize a pair of iPhones for 3D video capturing.
The UltraSync Blue generates Timecode that is passed via Bluetooth to six devices. (iPhones and supported Audio Recorders)
Using the Mavis Pro Camera app, it adds timecode to the video clips.
It makes editing in Final Cut Pro X so much easier, as I don't have to manually massage the clips. (The sync is frame perfect I think).
However, you can choose to shoot at 60fps.. and then only take the timecode from the box.
The iPhone 6s stutters trying to record 4K, 30fps with the Mavis app. (Update 4K, 24fps, 30mbit works, but not 4K 30fps)
One bug with the older version on the iPhone 6s, it prefers 23.98 vs straight 24p(?). (Best to manually select frame rate in the app, and not the Ultrasync blue) You don’t want to mix it up and have phones stupidly record at different frame rate.
The only video recording iOS app that supports the blue is the Mavis Pro Camera app. I wish more recording applications would support it.
(Unrelated, but the BlackMagic Camera app and seems to have some synchronization features built in, but I do not have another iPhone test with).
Here is some sample footage with a pair of iPhone 6s running the Mavis Pro Camera app.
The shutter speed is locked on both phones.
Strobing is an issue with higher shutter speeds, so ND filters should be used outside to smooth it out.
At 1080 60fps and match shutters on both phones and it works great.
