Asus Zenfone 4

While the Zenfone 5 offers a 720p display, on the Zenfone 4 you get a meagre 840 x 480 pixels resolution. Because of the smaller 4-inch screen size, the pixel density is an acceptable 233ppi, but the display isn’t as sharp as we’d like. Text on webpages appears jagged when zoomed in, and photos and videos don’t stand out either. The display is also highly reflective, so it isn’t ideal for watching videos. Unfortunately, the Zenfone 4 doesn’t feature an ambient light sensor, so you’ll need to adjust brightness manually. ASUS has provided a sliding meter to adjust brightness via the notification bar, but we still found ourselves having to tweak it frequently.On the plus side, the screen does get Corning Gorilla Glass 3 protection, a rarity on smartphones in this price range. And most importantly, it was very responsive, smooth and fluid to the touch, and great for typing too. 

Given its price tag, we didn’t expect much from the Zenfone’s camera, but it’s a definite improvement over the Moto E’s lone 5MP fixed-focus shooter. While the Zenfone 4 also offers a 5-megapixel snapper at the back, it does have autofocus. ASUS has also been generous enough to throw in a front camera with VGA resolution, which isn’t ideal for selfies but should suffice for Skype calls. The camera is also endowed with ASUS’ PixelMaster tech to improve image quality.    In auto mode, results weren’t very impressive, with close-ups showing evidence of grain and landscape shots appearing washed out. Images taken in low light are predictably grainy, and at night photos are too dark to make out much detail.The camera app offers several modes though, which drastically improve images. The Depth of Field mode works well for macros, keeping the subject in focus and creating a realistic blurry background. The HDR mode is one of the better ones we’ve seen on a smartphone, and the Night mode was surprisingly effective, bringing out more detail otherwise dark shots.There are a few other interesting modes available, like a Selfie mode that uses the primary camera, Smart Remove that lets you remove unwanted objects, and GIF Animation to (you guessed it) create GIFs.The camera also has several colour effects which you can apply in real time, such as Grayscale, Sepia, Pencil, Lomo, Negative and more. For more details, check out our ASUS Zenfone 4 camera review

The Zenfone 4 runs Android 4.3 Jelly Bean, with the custom ASUS ZenUI on top. ASUS has promised an update to KitKat, but it hasn’t arrived as yet. Like we noted in our Zenfone 5 review, ZenUI is one of the nicest skins we’ve seen on Android. Consisting of colourful icons and several useful apps and widgets, it offers several additions to stock Android, but doesn't cause the phone to become sluggish. The lockscreen displays shortcuts for calling, sending texts and accessing the camera, and displays the time and weather via the What’s Next widget. The app drawer has a handy feature to lock apps, just in case you want to prevent that pesky aunt from browsing through your embarrassing photos. The dialer app has been completely overhauled, and features a handy call-recording option too.

The Zenfone 4 is equipped with a dual-core Intel Atom Z2520 processor, clocked at 1.2GHz, and paired with 1GB of RAM and PowerVR SGX544MP2 graphics. The Zenfone 4 didn’t freeze during our two-week testing period and was fine for daily use, but we did notice minor lags when opening apps, especially straight after waking the device. Performance was smooth otherwise, with none of the sluggish behavior we found on the Lava Iris X1 (review).While the smaller display isn’t ideal for gaming, we were pleased to find that the intensive Riptide GP2 played smoothly on the Zenfone 4. Battery life is sadly an area where the device underperforms. The 1,600mAh unit can barely last a day with regular use, and heavy usage such as watching videos or gaming drains it much faster.