With smartphone sales stagnating in some markets, device makers have begun ramping up their innovation efforts with features like multiple rear camera sensors, hole-punch selfie cameras, and foldable form factors.

Now, something called Time-of-Flight (ToF) camera technology is all the rage. We've already seen Huawei use it, and maybe Apple will next. But what's it all about?

What is a Time-of-Flight camera?

  • Emits an infrared light signal
  • Measures how long the signal takes to return
  • Determines depth based on extracted data

A ToF camera uses infrared light (lasers invisible to human eyes) to determine depth information - a bit like how a bat senses it surroundings. The sensor emits a light signal, which hits the subject and returns to the sensor. The time it takes to bounce back is then measured and provides depth-mapping capabilities. This provides a huge advantage over other technologies, as it can accurately measure distances in a complete scene with a single laser pulse.

Oppo R17 ProWhat Is A Time-of-flight Camera And Which Phones Have It image 3

In comparison to other "3D-depth range scanning" technologies available, such as a structured light camera/projector system, ToF technology is relatively cheap. The sensors can reach up to 160fps, which means they're great for real-time applications such as background blur in on-the-fly video. Better yet, they use a small amount of processing power. And once distance data has been collected, features like object detection can be easily implemented with the right algorithms.

Note: ToF is one of many techniques that fall under range imaging. You may see it referred to as a range camera or even a 3D sensor.

What can a Time-of-Flight camera do?

  • Object scanning, indoor navigation, gesture recognition
  • Also helps with 3D imaging and improving AR experiences
  • Theoretically, it can better blur backgrounds in 'Portrait mode'

A ToF camera sensor can be used to measure distance and volume, as well as for object scanning, indoor navigation, obstacle avoidance, gesture recognition, object tracking, and reactive altimeters. Data from the sensor can also help with 3D imaging and improving augmented reality (AR) experiences. In phones, ToF camera sensors will likely be used for 3D photography, AR, and in particular Portrait mode.

Theoretically, ToF cameras can better blur photo backgrounds in Portrait mode. We say "theoretically" because the process still requires software magic, and in the end, it's up to a company to decide how it applies the data that the ToF camera collects.

ToF cameras can also assist in low-light situations - since the sensor uses infrared light to pick up "distance-to-subject", it could help smartphones focus even in pitch black.

Are Time-of-Flight cameras new?

  • Microsoft used ToF cameras in second-gen Kinect
  • LIDAR sensors use ToF cameras
  • Huawei’s Honor View 20 has a ToF camera

ToF technology isn't very new, as various companies have been experimenting with it for at least the past decade. Microsoft, for instance, used ToF cameras in its second-generation of Kinect devices. Lidar, which is popular in self-driving cars, also commonly features ToF sensors. Even drone companies have adopted them - this Chouette drone uses a TeraRanger ToF camera to surveil vineyards.

LGWhat is a Time-of-Flight camera and which phones have it image 2

So, while ToF cameras weren't invented yesterday, they're still cutting-edge and rapidly becoming more efficient, affordable, and accessible. For the first time, we're seeing ToF cameras appear in consumer smartphones, such as Huawei’s Honor View 20, which recently launched. Over the next couple years, we suspect many more flagship smartphones will debut with ToF camera sensors.

Which phones have a ToF camera?

Huawei P30 Pro

The quad camera setup - made in collaboration with Leica - not only implements the first 5x optical zoom periscope optic (it's 10x with hybrid zoom), it also features standard and wide-angle optics, alongside a ToF unit and LED flash. It's the most complete camera setup we've seen to date.

Samsung Galaxy S10 5G / Ultimate Edition

The forthcoming extra-massive Galaxy S10 that's kitted out to the nines is the 6.7-inch Ultra Edition. We first saw it termed as the S10 5G, as it brings the next-level connectivity speed with it, but this is also the only S10 model in the series to feature a ToF camera.

Oppo RX17 Pro

The Oppo RX17 Pro provides a 25-megapixel f/2.0 on the notch at the front, while the back features a triple camera set up with a ToF sensor.

Honor View 20

Honor's phone with the hole-punch selfie camera also houses a dual-camera setup consisting of a giant 48-megapixel unit with a "3D ToF sensor" and LED flash.

LG G8 ThinQ

The LG G8 ThinQ, announced at Mobile World Congress 2019, uses ToF camera sensor technology.

iPhone 2020

Bloomberg claimed Apple's next-generation iPhone in 2020 will feature a new TrueDepth system with Time-of-Flight 3D cameras. Apple reportedly want to offer a more detailed AR experience, complete with accurate depth perception and placement of virtual objects. 

Who makes Time-of-Flight camera sensors?

Sony makes next-generation 3D sensors with ToF technology, and the Japanese company is supposedly ramping up production after getting interest from Apple.

Other ToF camera sensor manufacturers include AMS/Heptagon, ASC TigerCub, TeraRanger One, Riegl, Lucid/Helios, and AdaFruit.