Asus ZenFone AR (ZS571KL) Smartphone Review

But what exactly are Tango apps? Basically, a Tango app is an Android application presenting one or several overlays to the camera viewfinder’s live image. Most of them are mere gimmicks at this point. Let us take “Slingshot Island” for example: it transforms your smartphone into a slingshot that allows you to sling rocks at virtual castles in your surroundings. Some educational value can be found in Solar Simulator, an app that presents you with a to-scale solar system model and allows you to travel back and forth between the planets. The measure app, on the other hand, is a virtual tape measure: you set a starting and an end point and get the distance between the two shown on your screen.

And while most Tango apps are gimmicks at this point, some of them are excellent showcases for the high potential of AR applications in the near future. For example, BMW’s i Visualizer allows you to take a virtual seat inside a BMW i3, i3s, or i8 and fiddle around with its controls (e.g. turn on the lights or open the doors). And it gets even more interesting when combined with Google’s Daydream View Headset 3D glasses: that way you can inspect the BMW models very closely and realistically prior to purchasing one. Thanks to the phones high-resolution WQHD display virtual quality and the subsequent 3D effect are top notch.

Dressing and virtual furniture apps, such as Dressing Room, Lowe’s, Wayfair, or iStaging offer a similar experience. Dressing Room, for example, allows you to dress up a mannequin modelled after your exact measurements to your liking and purchase the clothes right away. Lowe’s, Wayfair, and iStaging allow you to place virtual furniture and decorative items in your rooms to see how well (or bad) they would actually look in that particular space. Unfortunately, these apps lack a zoom feature and virtually furnishing a small room can become quite finicky.

All this is possible thanks to the ZenFone AR’s dual camera system. The cameras memorize the three-dimensional coordinates of objects very accurately and allow the user to literally walk around the virtual items in order to look at them from all sides. Occasional hiccups include a slight shift in proportions between the real environment and the virtual object in question, and those can most often be solved by simply moving the smartphone slightly thereby changing the viewing angle between the camera and the virtual object.

Measuring distances worked surprisingly well if the two end points were within 2 m (approx. 7 ft) of the user and assuming the aiming was performed accurately. But even then the measuring app did sometimes focus on the wrong spot rendering the measurement obsolete. In addition, the app had trouble with objects that were farther away (more than 10 m/33 ft).

Overall, the AR experience with the ZenFone AR was much better than the AR experience with the Lenovo Phab 2 Pro. Not once did we experience slowdowns or graphical glitches in Tango apps, and while the ZenFone AR did get noticeably warm up, it never reached the point where it got uncomfortable to hold. However, surface temperatures become less of an issue anyway once the phone is installed in virtual reality glasses.

Location services support positioning via GPS, GLONASS, and BeiDou, and position lock was obtained fairly quickly, even indoors with an accuracy of 6 m (~20 ft; 5 m/~16 ft accuracy outdoors).

We examine a smartphone’s GPS accuracy on an 8.8 km (~5.5 mi) long bike ride, where we compare it to a professional Garmin Edge 500 GPS. The ZenFone AR did very well in this test. At the end of the ride, the difference between the two was just 50 m (~55 yd), and occasionally, the ZenFone AR was more accurate than the Garmin Edge 500. Thus, the ZenFone AR is quite suitable for everyday navigation purposes.

The ZenFone AR’s main camera features a 4K capable 23 MP sensor with f/2.0 aperture, 4-way optical image stabilization (OIS), three-way electronic image stabilization (EIS), a dual LED flash and a 77 ° field of view. The sensor behind all this is Sony’s 1/2.6-inch Exmor RS IMX318.

Asus refers to the main rear camera as TriCam due to the fact that two extra cameras are installed in addition to the main camera. The first is used for motion detection, the second for measuring the distance to and between objects and general depth of field visualization. All three cameras are required for Google’s Tango. The main 23 MP camera is accompanied by an 8 MP shooter at the front.

In bright daylight, the main camera’s image quality is very decent (see scenes 1 and 2), with vibrant colors and a high dynamic range. However, Unlike its competitors, some photos taken with the ZenFone AR tend to lack sharpness and fine details. Low-light quality is only so-so. Our sample photo (scene 3) seems blurry at first sight already, and upon closer inspection it lacks details quite visibly. Video recording quality (max. 4K/3840x2160 @ 30 FPS) is very decent.

The extensive camera app is noteworthy. It allows access to all relevant settings, including manual shutter mode, bokeh, and face detection. The app also supports raw photography (extension: DNG) and its image improvement algorithms work their wonders on the front-facing 8 MP camera as well. Unfortunately, the front-facing camera supports only 1280x720 @ 20 FPS video recording.

ZenFone AR’s WQHD (2560x1440) Super AMOLED panel is protected by Gorilla Glass 4, and the phone’s screen to body ratio is 79%. Considering the comparatively small display size, the resulting pixel density is an impressive 515 PPI, and individual pixels are not distinguishable with the naked eye anymore. Due to its OLED nature, each pixel can be individually enabled or disabled, meaning that the display does not require a uniform backlight anymore. Accordingly, blacks are really black.

The display’s maximum brightness of 341 nits is not bad, but it is also nothing to write home about considering that it got bested by every single one of its competitors by a significant margin. The real-world APL50 test with evenly distributed bright and dark areas results in a maximum brightness of 402 nits, and the ZenFone AR’s brightness distribution is very decent at 90%.

Unfortunately, the display flickers at a low 231.5 Hz, meaning that it is being turned off and on again 231.5 times per second. Sensitive users might notice this low-frequency flickering. On the other hand, the display comes with a blue light filter and a very low minimum brightness of 7.06 nits, both of which help to reduce eyestrain in the evenings and in low-light environments.

Even under full load the phone never got uncomfortably warm. After around one hour of maximum load the hottest spot we found was measured at just 37.9 °C (~100 °F), and the average temperature at the front was 34.9 °C (~95 °F). When idle, it reached no more than 25.3 °C (~78 °F) on average.

We found no evidence of throttling, even under full load. In GFXBench’s Manhattan ES 3.1 scenario, the frame rate remained consistently high even after 30 reruns.

With a maximum sound level of 88.4 dB(A), the ZenFone AR’s mono speaker located at the bottom of the phone can become fairly loud. Mids and Highs are nicely balanced, but as usual the smartphone lacks bass. Accordingly, the soundscape is rather tinny and thin, but certainly sufficient for the occasional YouTube or Spotify experience. The integrated sound chip is capable of high-resolution audio output at 24 Bit/96 kHz or 24 Bit/192 kHz.

Not only does the included headset improve the sound quality immensely, it also supports DTS Headphones:X 7.1 Virtual Surround sound. Unfortunately, the source material has to be encoded appropriately to benefit from this. 7.1 sound samples, for example in movie trailers, can be found here.

No doubt: the ZenFone AR is the first smartphone to run Google’s augmented reality Tango apps smoothly. However, given the relatively low selection of apps (around 30) - most of which are gimmicks to boot - in its current state Tango is far from being a must-have feature. The question is: are you willing to spend almost $800 plus tax for this rather poor AR experience? We suspect that for most users, Tango is not going to be a major factor when considering the ZenFone AR, especially since Google’s Daydream VR glasses are not included and must be purchased separately.