No matter what camera you use, the ability to focus remotely is a wonderful thing. And if you’re filming yourself, it can often be invaluable. I’ve spoken about it before in the Weebill 2 Pro Plus Kit review. And while I tend to avoid it when shooting video, I’m not to big to admit that there are times when autofocus can also make your life drastically easier.
Autofocus is a feature notably lacking from Blackmagic cameras, but this iPhone app gives it back to you using your iPhone’s LiDAR sensor to determine the distance to the subject and telling your camera to focus to it. And, yeah, you get regular remote focus pull features, too. It looks like the app’s been out for quite a while, but has kept itself below the radar (their Facebook page only has 5 followers). YouTuber Michael Tobin discovered it, though, and has made a video showing how it works.
The app is called Focus Puller and it costs $12. It only runs on the iPhone and requires iOS 14 or later. It connects to your Blackmagic camera over Bluetooth and requires that you use an autofocus lens that has electronic communication with the camera. I mean, that makes sense. It can’t autofocus your manual lenses. Any lens that you can touch-to-focus normally on the Blackmagic cameras should work, though.
By default, the app just works like a regular remote focus with a slider that you can use to adjust between minimum focus distance and infinity. And looking at Michael’s video, it’s pretty responsive, too – probably more responsive than using a motorised follow focus unit with a wheel on your gimbal! But you can add markers to this to have preset focus distances to jump straight from one specific marker to another.
What’s particularly interesting, though, is that it can utilise your iPhone’s LiDAR sensor in order to determine the distance to your subject and send commands in real time to your Blackmagic camera to adjust the lens focus to match it. There is some calibration involved, and unlike other LiDAR solutions, the app gives a lot of calibration points to ensure your phone and your camera are always synced up.
I expect if you’re using a zoom lens that’s not parfocal, then the calibration won’t work all that well throughout the focal range. It’s also limited to only looking at the centre of your shot on the iPhone (possibly a limitation of the sensor built into the iPhone), but it actually looks like it’s a lot more useful than other options on the market. It’s a heck of a lot cheaper, too, if you’re already an iPhone user!
You can download the Focus Puller app for free from the Apple App Store to have a play with it and check that it works for you and your lenses. But once you want to hit the record button, you’ll need to pay the $12 cost to unlock it.