World’s First Smartphone To Feature Active Autofocus Is Here
Here’s How LG G3's Laser Autofocus Sets It Apart From The Crowd
Active Autofocus: How Laser Autofocus Works
Laser Autofocus is an example of what is called as Active Autofocus, or more specifically LG’s specific implementation of it. Active Autofocus works in a far more straightforward way than Passive Autofocus. It’s called Active because it works independently of the optical system and hence requires extra hardware — it requires an emitter and a receiver.
To put it as simply as possible, Active Autofocus works in precisely the same way as SONAR/RADAR. Basically, a beam of ultrasonic or electromagnetic waves is shot at the subject by an emitter and a receiver waits for the reflected beam to arrive. The time between emission and reception is calculated, and since the velocity of ultrasonic/electromagnetic waves in the given medium (i.e. air) is already known, the distance between the camera system and the subject can be easily calculated using the echo formula (v = 2d/t). After gaining knowledge of the distance of the subject from the camera, the system moves the lens system accordingly. And with that, you’re done. Pretty neat, innit? Furthermore, this kind of autofocus works just as well in low-light situations, quite unlike contrast-based Passive Autofocus systems.
LG’s Laser Autofocus system has an emitter that shoots an Infrared laser beam. “Laser”, while also serving to add some mega marketing punch, simply means that the beam is collimated and doesn’t disperse. LG also claims that their Laser Autofocus takes less than a third of a second to complete its job, making it one one of the fastest Autofocus systems in a smartphone. But like I said before, whether their claims hold any water is yet to be seen.
But anyway, that’s basically how the LG G3’s Laser Autofocus works.
. It's the final pre-production build so they can move forward with invites/sales soon
...i was so used to using MX Player...Never gave it a second thought.
