Imaging technology behind the ASUS ZenFone 4 series’ cameras.
With a tagline like ‘We Love Photo’ accompanying the launch of its phones, there’s little wonder as to which part of the phones ASUS has invested the most in. Prior to the regional launch of the ZenFone 4 series, we were invited by ASUS to join a technical seminar to understand what the cameras and imaging technology that went into the new phones have to offer.
The imaging technology behind ASUS smartphones has always used the PixelMaster name. “So what’s new with version 4.0?” you may ask. To put it simply, it’s a collection of improvements to help you take better pictures with the ZenFone 4 and ZenFone 4 Pro. The improvements that make up PixelMaster 4.0 are not revolutionary on their own, but they all come together in helping you to capture better photos.
IMPROVED LOW-LIGHT PERFORMANCE
The first two elements are pretty self-explanatory. A larger aperture means more light going to the sensors and Optical Image Stabilization (OIS) compensates for any shaking going on while the shutter is open. All these help you take better photos when in challenging lighting conditions, which is a common weakness of smartphone photography.
If you’ve noticed, many other smartphone manufacturers are beginning to use sensors with lower pixel count, while still claiming better detail retention. This is because the pixels here are larger than before. In the case of the PixelMaster 4.0, the ZenFone 4 series of phones are predominantly using the Sony IMX362 sensor, boasting 1.4 m pixels instead of the usual 1.0 m pixels. This slight increase means a 96-percent increase in light intake.
DUAL PIXEL PDAF
ASUS says that, back in the day, the duty of autofocus has only been relegated to a very limited number of pixels, sometimes as little as five percent of the total pixel count. Dual Pixel Phase Detection Autofocus (PDAF) here gets all the pixels involved in the process, which results in achieving focus in as little as 0.03 seconds.
SelfieMaster 4.0 for the front-facing cameras builds on the tech of PixelMaster 4.0, but with a few extras for the selfie crowd. And we start with the front-facing camera of the ZenFone 4 Selfie Pro.
24M PIXELS FROM A 12MP SENSOR
While it uses the same Sony IMX 362 sensor as the rear cameras of the ZenFone 4 and ZenFone 4 Pro, it is touted to have 24 million pixels instead of the usual 12 million. To explain this, we go back to the IMX362 sensor itself, and Dual Pixel PDAF technology. As we mentioned, the IMX362 sensor uses 1.4 m pixels that take in up to 96 percent more light per pixel than the usual 1.0 m pixels of the standard sensor. This translates to having twice the number of light-capturing photodiodes per microlens compared to conventional sensors, which is used in Dual Pixel PDAF.
ASUS tweaks this so that the IMX362 sensor on the front-facing camera sacrifices Dual Pixel PDAF to split the individual pixels into two. This creates a 24MP photo that captures more detail, at the expense of the advantages afforded by the larger pixels and Dual Pixel PDAF. That said, it still works better than the usual interpolation, which stitches four 13MP images together to form an artificial 52MP image that doesn’t quite stand up to scrutiny.
In addition to the smart tweaking of a 12MP camera into producing 24MP images, SelfieMaster 4.0 also means that the front-facing camera of the ZenFone 4 Selfie Pro can record videos in 4K resolution.
Beautification effects are now commonplace on front-facing cameras. But while it is indeed common in beautifying still images, you have always been able to preview your desired level of beautification before you actually take the shot. ASUS takes this a step further by allowing your videos – both livestream and recording – to be beautified as well.