Your iPhone is set up as a still camera first and foremost, so it tends to automatically focus and expose your images. This is fantastic when you need a quick snapshot, but when you’re taking video, the constant re-focusing and exposure adjustment just makes everything look blurry and amateur.
You can tap the screen in either video or photo modes to get a quick adjustment, but the minute you or or subject moves, all bets are off. Your best chance, then, at keeping your iPhone videos blur-free is to lock the focus and exposure.
To activate this lock when filming, simply launch the Camera app on your iPhone, and set it to Video. Now, tap and hold on the screen where you want to set the focus and exposure; this is usually the subject of the video in the foreground, but feel free to play around with it if you’re getting creative.
Hold your tap until you see the “AE/AF Lock” icon show up on your screen. Now the focus and the exposure will be set to the value of whatever you tapped on. You’ll need to stay in the same place as when you locked the values, since they’ll only work the same distance away from and lighting environment of your subject as when you set them.
To deactivate lock, just tap on your iPhone screen or hit the Home button to close the Camera app, and the AE/AF lock will cancel, taking you back to auto-adjust mode.
This feature works across all modes on my iPhone 6 Plus, including panorama, slo-mo, and time-lapse.
Now you can take those videos without worrying about the auto-adjust blurriness. Hooray!