【Tips and Tricks】Laser autofocus Q&A

The ASUS digital imaging technology division saw that many ZenFans were unaware and really curious about laser autofocus on newer ASUS ZenFone products such as the ZenFone 2 Laser, Selfie, Max and Zoom, so they specifically provided this information for us to discover what laser autofocus is, how it works, and what it does to help out during camera lens focusing.

What’s the principle of laser autofocus?
The laser autofocus system uses a laser beam transmitter along with a proximity sensor to calculate the time for the laser to be transmitted, reflected and return to determine the distance of the object, and then feed it to the system, so the voice coil motor (VCM) inside the camera that controls focusing can know the distance and quickly determine which direction the lens must move. Whereas traditional focusing, which uses contrast detection, cannot quickly determine the distance of the focusing object and must perform full-scale scanning to find the clearest focusing point. This is why the speed of laser focus is a lot faster than traditional focusing. Laser focus can fully exert its capability especially under environments with low lighting; for certain scenarios, the speed of laser focus can be twice as fast as traditional focusing!

Does the laser autofocus still work while using touch auto focus (TAF)?
In the current version, it will switch back to traditional focusing when using touch auto focus; therefore, those of you who use TAF to compare with the speed of laser auto focus, you won’t be able to feel the lightning fast focusing speed! However, after hearing the voices of ASUS fans, ASUS plans to also enable laser auto focus when using TAF at the middle of the screen in future firmware updates; please remember to update your phone when the new firmware comes out!

Does laser focus have distance limitations?
Whether it is object focusing for close distances or far distances, the direction which the VCM will move is determined according to the distance returned by laser focusing; therefore users can enjoy fast focusing experience for all distances. Please refer to this video:

How can I make sure that the laser focus on my phone is functioning properly?
You can hold your phone in your hand and use printed objects, such as business cards, to move it in front of the camera; when the object enters the camera’s visual angle, observe whether the camera will quickly focus on the nearby object, and whether the camera will quickly focus on distant scenery when you moved the object out of the camera’s visual angle. This way you can confirm whether the laser focus is functioning properly.

What’s the difference between laser auto focus and phase detection AF?
Laser auto focus and phase detection AF (used by the newer iPhones) each has their own unique hardware and focus operation principles. Under sufficient lighting, the focusing speed of the two are almost the same; but when you’re in a low light environment, laser auto focus can show its advantage and still maintain quick focusing performance.

Will laser autofocus blind me? I'm scared!
Laser auto focus has passed laser safety regulations, and it absolutely will not cause any injuries to the user. When you turn on the camera and look behind the phone, you can see that there’s a red light flashing behind the black protective glass; that is the proof that laser auto focus is working hard to detect the distance, and we guarantee that this red light will not injure your eyes!

Have more questions that these didn't answer? Feel free to ask us! First 10 members to ask will get free 5 credits!

Shared from ZenTalk Taiwan, and the author is ZenTalk_喬伊 (Joey)
Link: http://www.asus.com/zentalk/tw/forum.php?mod=viewthread&tid=107919

Hi Nikko, Does Laser Auto Focus also works on Video Mode?                  

andrew_gonz posted on 2016/2/2 15:15
Hi Nikko, Does Laser Auto Focus also works on Video Mode?

Yes, it works continuously while in video mode.

Why does the laser ruler have a limit on the distance it can measure?

optimalgurl posted on 2016/2/2 17:04
Why does the laser ruler have a limit on the distance it can measure?

While the laser is accurate enough for camera autofocus at it's current strength (weak enough to pass safety regulations), beyond 50cm it is no longer accurate enough for precise measurements.

Sir Nikko, bakit po minsan kapag ginagamit ko po yung front cam using beautification, medyo delay yung shot?

Hi, when I block my laser completely with my finger it shows a distance of .6cm and sometimes .9cm, shouldn't it show a distance of 0cm? Even if I put a space between my finger about less than .5cm it still shows a distance of .6 or .9cm. Is it normal or is my laser focus not really accurate enough?

nJUC posted on 2016/3/7 08:50
Hi, when I block my laser completely with my finger it shows a distance of .6cm and sometimes .9cm,  ...

Hmm..

My best guess is that the laser also measures the distance between the actual module, the glass covering the sensor and your finger, that's why it doesn't measure exactly 0cm.