The ASUS ZenFone 2 Review
by Brandon Chester on May 26, 2015 8:00 AM ESTVideo Performance
The other side of a phone's camera quality is how it performs when taking video. I've actually noticed an increased number of people taking videos now that the warm weather of summer has returned to Canada. Taking videos is also arguably a more intensive test of camera quality than taking still photos. A device's image signal processor needs to do post-processing in a much shorter time interval, and on devices where OIS is supported there's no way to use it to enable long exposure times as the frame rate of the video needs to be fixed high enough to keep the illusion of motion intact.
The ZenFone 2 has 3 different video settings, although the first one is 480p and not really worth discussing. The other two are the 720p30 and 1080p30 modes. While one may be tempted to just use the highest resolution mode, the caveat with 1080p30 recording is that there's no form of electronic video stabilization. ASUS also has a setting for choosing between quality and performance when recording. I assume that the performance setting is reducing frame drops at the expense of bitrate, but I didn't notice any difference in smoothness between the two modes so I recorded all the test footage using the quality setting.
The first video test is a video taken from a relatively stationary position. This gives an idea of what video quality is like without the effects of hand shake and so the device's ISP is really what will determine whether a device does well or not. I've taking recordings in both the 720p30 mode with digital stablization, and the 1080p30 mode without the EIS.
In this test the 1080p mode is the clear winner. The impact of EIS when recording at 720p is minimal, and the 720p footage is so blurry that it almost looks like upscaled 480p footage. The ZenFone 2 encodes 720p footage at 8Mbps using the H.264 Baseline profile. 1080p footage is encoded at 15Mbps and also uses H.264 Baseline. Unfortunately, even the 1080p footage isn't very impressive. There's just a general lack of sharpness throughout the entire frame.
The next test makes things more interesting by adding a significant amount of camera movement. This is where the use of EIS in the 720p mode will come into play, while the 1080p mode will most certainly have a higher degree of shakiness.
In this test it's clear that the 720p is much more stable than the 1080p footage overall. However, there are numerous instances where the the camera moves too far from its original position and the video drops frames as it settles on a new position. There's also a significant amount of high frequency shaking which makes the entire video look like it's wobbling back and forth very quickly. Both of these issues are very similar to what you see with video that is stablized using OIS, which is strange because the ZenFone 2's camera doesn't have OIS.
Unfortunately, the 720p video is again very blurry. The 1080p video is better, but is also not near as good as the output from other smartphones. It doesn't appear that there's any degree of EIS being used to stabilize the 1080p footage either. Both modes suffer from some noticeable processing issues, including halos where branches of trees are in front of the sky.
At this point it's becoming fairly evident to me that the ISP is being used in the ZenFone 2 is very far behind the competition. It would be nice if ISPs in mobile were less opaque so we had a better idea of what goes on at that stage in the pipeline. Whatever the cause may be, the ZenFone 2's video output is fairly uninspiring. If you do need to take a video with it I would still use the 1080p mode despite the shakiness, as the 720p mode is just far too blurry.
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jt122333221 - Tuesday, May 26, 2015 - link
Heads up - it also supports double-tap to sleep. Unfortunately, you have to double-tap on a completely empty portion of the display (empty homescreen or in the notification bar) to get it to sleep.mkozakewich - Tuesday, May 26, 2015 - link
Put Cherry Trail in here with Window 8 (and then 10) and it would totally be what I'm looking for in a phone. I'm going to have to keep my eyes open.commenter001 - Tuesday, May 26, 2015 - link
I just bought the 4GB model. I've actually been using it more than my S6! What the review kinda skipped on was real world usage of the device. This thing doesn't skip a beat. It's amazing how many apps you re-open and they're right back where you left them (hours ago). Unlike the S6 where it seems to reload every dang time just after normal usage. The power button is not a big deal, I use the double-tap on the screen to wake it up all the time.The battery life is not that horrible, gets me through the day and I'm in poor cell area most of the time. Video and pictures, yeah, they're pretty average.
Again, I'm amazed at the lack of the usual lagginess that I've come to accept from Android. Maybe it'll creep up over time but so far this phone is on par or exceeds the S6 just in real world day-to-day stuff for me.
ketacdx - Thursday, May 28, 2015 - link
I agree man, this thing is surreal for real world usage. Battery really is pretty decent, mine is about 2% right now with 24 hrs on, 3hrs49mins of which are screen on time. Only thing I notice with mine is Android OS is using 31% of battery with CPU total at 10hrs 16 mins. I can only assume a glitch or Android issue that hopefully repairs with updates. Either way, pretty decent!! :)blzd - Thursday, May 28, 2015 - link
I'd say that's less of an accomplishment from Asus and more of a standard failing from Samsung and Touchwiz.Have you tried any other recent Android devices? Nexus devices and Motorola using stock Android have felt just as snappy and fluid for years now and it's only gotten better with Lollipop.
hans_ober - Tuesday, May 26, 2015 - link
How would this compare to the Xiaomi Mi 4i? In India, the lowest model of the Zenfone 2 is price competitive with the Xiaomi Mi 4i, which I hope AT manage to get their hands on.aryonoco - Wednesday, May 27, 2015 - link
Great article. Thanks to your work Brandon, I'm beginning to not even miss Brian any moreThis was a pleasure to read. Thank you.
lvchubby - Wednesday, May 27, 2015 - link
I'm a newcomer and respect Anandtech's true reviews instead of some others which look like marketing articles, but there's something missing about this review. I agree that the device is very value for money, but there are also quite a large number of complaints on Taiwan's user forums (in Chinese of coz) about QC and compatibility issues every time Asus launch a new phone in Taiwan. Sadly it happens repeatedly and Zenfone2 is not an exception, and still many people bought it due to it's CP value. Some of them were blaming Asus for using them as beta testers before the international launch. That's why I'm still holding up my decision.I'm not saying the Zenfone2 is not a good device, but for those who wanna buy it, I'd suggest holding up your decision for a few months till Asus hopefully solving most of the compatibility issues by software updates. Also check carefully for any faults when u receive the device.
As a side note, there are some local reviews/users saying the 3Gb RAM is not quite enough as the Zen UI eats up much RAM, and 4Gb RAM version is recommended.
chrnochime - Wednesday, May 27, 2015 - link
You mean like this thread from mobile01(yeah I read Chinese too):w w w . mobile01 . com/topicdetail.php?f=588&t=4395771
Hopefully this will force them get their shit together since they're now selling in the US...
lvchubby - Wednesday, May 27, 2015 - link
U can find similar posts even in Asus' own forum:http://w w w . asus . com/zentalk/tw/forum.php?mod=forumdisplay&fid=174
And imo it's a shame that the CEO admitted the beta tester thing...
http://w w w . mobile01 . com/topicdetail.php?f=588&t=4332578