ASUS ZenFone Zoom S review: The first ZenFone with dual rear cameras

Overview

Taiwanese electronics and components maker ASUS adds another phone to its ZenFone range, and it’s called the ASUS ZenFone Zoom S. This phone is the successor to last year’s ASUS ZenFone Zoom, and it is also part of the ASUS ZenFone 3 product family. Speaking of which, whatever happened to the ASUS ZenFone 3 Zoom that was actually launched at CES 2017 and was previewed by HWZ? Well as it turns out, they are both the same phone with the same model number (ZE553KL), but the local ASUS team wants to market it as the Zoom S.

As its name implies, the ZenFone Zoom S (ZE553KL) is a phone that emphasizes on its smartphone-photography capabilities. To that end, this phone comes with a dual rear camera setup – a first for ASUS and the star feature of the phone. They are both specced at 12 megapixels with very different purposes – the main one packs a Sony IMX362 sensor, and it’s further assisted 4-axis OIS (optical image stabilization).  The accompanying Zoom Camera has a fixed 59mm focal length (35mm equivalent), giving it a fixed 2.3x optical zoom.

While the preceding ZenFone Zoom had a higher megapixel count along with a further 3x optical zoom, imaging performance was average at best even when compared against non camera-centric smartphones. This left a lot of room for improvement, and makes us hope that the succeeding ZenFone Zoom S will measure up in this department.

Under the hood lies a Qualcomm Snapdragon 625 SoC – if you recall, this was also present in the ZenFone 3 base model. This means that the ZenFone Zoom S is a 'mid-range offering', with the premium ASUS ZenFone 3 Deluxe taking the current line-up’s flagship spot. With a massive 5,000mAh battery capacity, it also seeks to redress what the 4,100mAh ZenFone 3 Max didn’t manage to achieve and hopefully help shutterbugs enjoy more photography time.

Will the ASUS ZenFone Zoom S be the maverick device that melds all the best of what we hope to see from the ASUS ZenFone lineup and surpass the mark set by the ZenFone 3? Let's find out in this review.

ASUS ZenFone Zoom S compared with its predecessor
  ASUS ZenFone Zoom S ASUS ZenFone Zoom (ZX551ML 128GB)
  ASUS ZenFone Zoom S ASUS ZenFone Zoom (ZX551ML 128GB)
Launch SRP
  • From S$678
  • From S$729
Operating system
  • Android 6.0 with ASUS ZenUI 3.0
  • Android 5.0 Lollipop with ASUS ZenUI
Processor
  • Qualcomm Snapdragon 625 octa-core, 2.0GHz
  • Intel Atom Z3590 2.5GHz quad-core processor
Built-in Memory
  • 4GB RAM
  • 4GB RAM
Display
  • 5.5-inch / 1,920 x 1,080 pixels (~401 ppi) / AMOLED
  • 5.5-inch / 1,920 x 1,080 pixels / IPS
Camera
  • Rear (main): 12-megapixel, f/1.7, TriTech+ AutoFocus, 4-axis OIS
  • Rear (secondary): 12-megapixel, f/2.6
  • Front: 13-megapixel, f/2.0
  • Rear: 13-megapixel, 10-element Hoya lens, PixelMaster, laser autofocus, optical image stabilization and dual-LED real tone flash
  • Front: 5-megapixel, PixelMaster
Connectivity
  • Wi-Fi 802.11 a/b/g/n/ac, Bluetooth 4.2, USB 2.0 Type-C, Wi-Fi Direct
  • Wi-Fi 802.11 a/b/g/n/ac, Bluetooth 4.0 +EDR, NFC, GPS, GLONASS, QZSS, SBAS, BDS
Storage Type
  • 64GB storage (expandable via microSD, up to 256GB)
  • 128GB internal storage space
  • microSD support up to 128GB
Battery
  • 5,000 mAh
  • Reverse charging (1A)
  • 3,000mAh
Dimensions
  • 154.3 x 77 x 7.99 mm
  • 158.9 x 78.84 x 5 ~ 11.95mm
Weight
  • 170g
  • 185g

 

Design & Handling

While the ZenFone 3 was stylized like a Sony Xperia phone, the ZenFone Zoom S shared the same design language with flagship phone models like the Huawei P10 and the Xiaomi Mi 6 (which in turn, was inspired by iPhone 7’s physical design). Right off the bat, it’s understood that the Zoom S departs from the base model’s appearance (ZenFone 3), but it’s not entirely original.

The ZenFone Zoom S uses an aluminum alloy body with a sandblasted matte surface. The edges and corners are rounded, like the P10 Plus and Mi 6. ASUS also borrowed design influences from the ZenFone 3 Max – it kept the two polished antenna lines. This is largely different from the ZenFone 3 and ZenFone 3 Deluxe, where they had no visible antenna lines running across the back of these devices.

The front features a 2.5D glass with contoured edges, and it’s finished with a coat of Gorilla Glass 5. The contoured edges lend the seamless-looking appearance, and it meets the metal body at the chamfered edges. This provides a tactile response that signals the edges of the display to our fingers, at the expense of an all-out seamless feel that many of the flagship phones are starting to boast. Chamfered edges like these can't be found on the P10 Plus or the newer iPhones, so it doesn’t feel the same as using these rivals.

With its 7.99mm thin profile and 170g weight, the phone feels light and sleek like the P10 Plus, and it's comfortable when gripped in one hand. However, the width of the ZenFone Zoom S requires you to utilize both thumbs in order to comfortably operate the device in day-to-day handling.

The ASUS ZenFone Zoom S (64GB) is available locally in three colors - Navy Black (this review model), and Rose Gold. Glacier Silver is not available in Singapore.

 

Display & Audio

On this device, you’ll find a 5.5-inch AMOLED display that handles Full HD resolution (1,920 x 1,080 pixels). Like most typical AMOLED displays, the Zoom S exhibited a warm color temperature (check those snow-capped mountains out). It’s also vibrant and bright, and it has no issues rendering minute details, such as highlights and mild differences in hues.

Like the ZenFone 3, the ASUS ZenFone Zoom S uses a "5-magnet NXP Amp" speaker. By itself, the phone's speaker is very loud for its size. We don't think it's actually different from the ZenFone 3 in this aspect. The ZenFone Zoom S also has the 3.5mm audio port – it's located to the left of the USB charging port. Elsewhere in the audio department, the Zoom S has been certified for Hi-Res Audio, making it compatible with fellow Hi-Rest Audio headphones. The phone can playback audio files saved at 24-bit/96KHz or 24-bit/192KHz audio resolution.

 

UI & Features

While the ZenFone Zoom S ships with Android 6.0 (Marshmallow) OS, ASUS said that the phone can be updated to Android 7.0 (Nougat) OS within the first half of 2017. This would give the phone the ability to shoot images in RAW format, but for now it doesn't support this even though the device is camera-centric in nature. Meanwhile, the current iteration of the ZenUI is more palatable than the previous iteration as they've toned down on the juvenile-looking gradients in their stock apps.

 

Dual SIM, dual standby

Both of the ZenFone Zoom S nano SIM card slots are compatible with 2G, 3G, and 4G networks, but only one SIM card can connect to a 3G or 4G network at any one time. The second nano SIM card slot can double up to take in a microSD card to expand the phone's built-in 64GB storage space. This dual SIM, dual standby configuration is quite common in modern Android smartphones as well – the ZenFone 3 supported dual SIM in the same manner.

 

USB-C port with reverse charging

The USB Type-C port (at USB 2.0 speed of course) on the ZenFone Zoom S also supports reverse charging at 1.0A. Yes, it’s also possible through the ZenFone 3 Max, but the latter’s USB OTG charges other devices at just 0.5A. Since the Zoom S uses a USB Type-C port, ASUS provided a Type-C to Type-B adapter in the retail box as many devices still rely on the older USB Type-B port.

 

Fingerprint sensor

ASUS expectedly brought over their fingerprint sensor feature to the ZenFone Zoom S. In the same fashion as the ZenFone 3 and ZenFone 3 Deluxe, the sensor is also located at the rear. The furrowed square-shaped sensor features a chamfered edge that’s helpful when you need to guide your index finger to the scanning area. ASUS said that the decision to change to a square shape (from the oblong sensor on the ZenFone 3) makes the phone appear sleeker. Funnily enough, the on-screen setup instructions still depict the sensor as a rectangle. That said, you can register up to five fingerprints on the device.

One notable claim from ASUS is that the fingerprint sensor has a 0.3-second unlock time. In actual use, we found that it actually worked rather swiftly, possibly justifying their claim. Even from a locked state with a blank display, it instantly registers our finger once it meets the sensor.

There are other optional fingerprint-related features that can be activated within the settings app. There’s one that lets you pick up calls when the phone is ringing, which is handy when you simply want to lift your phone off a table and start chatting away. Double-tapping the sensor (while the phone isn’t locked) launches the camera app.

There’s also the option to snap photos via single-tapping on the fingerprint sensor while in camera mode. However, we believe that using two hands for photo-taking provides more stability. That, in turn, makes the fingerprint-snapping option redundant due to its placement and purpose.

 

No NFC

Since the fingerprint sensor is so awesome, it should be a cinch when paying via cashless mobile methods such as Android Pay, right? No, because the ASUS ZenFone Zoom S has no NFC support. We found this strange since the previous ZenFone Zoom did have NFC. ASUS could not comment to us when we asked why this feature has been removed in this day and age as well as class of device.

Benchmark performance

The ASUS ZenFone Zoom S uses a Qualcomm Snapdragon 625 SoC – that’s the same processor used in their ZenFone 3. Our unit came with 4GB RAM with 64GB internal storage; Singapore will not officially get the 128GB storage option.

These specs place the ZenFone Zoom S in a hotly-contested space. By now, we have a decent selection of phones powered by the Qualcomm Snapdragon 625 processors available in Singapore, across a huge price range. We'll be comparing many of these devices in our comparison.

  ASUS ZenFone Zoom S ASUS ZenFone 3 Moto Z Play Oppo R9s Samsung Galaxy A7 (2017) Xiaomi Redmi Note 4
  ASUS ZenFone Zoom S ASUS ZenFone 3 Moto Z Play Oppo R9s Samsung Galaxy A7 (2017) Xiaomi Redmi Note 4
Launch SRP
  • From S$678
  • From S$498
  • From S$699
  • From S$679
  • From S$648
  • From S$259
Latest Price
  • From S$630
  • From S$500
  • From S$215
Operating system
  • Android 6.0 with ASUS ZenUI 3.0
  • Android 6.0 with ASUS ZenUI 3.0
  • Android 6.0 OS (Marshmallow)
  • ColorOS 3 based on Android 6.0 Marshmallow
  • Android 6.0.1 Marshmallow
  • MIUI 8.2 based on Android 6.0.1
Processor
  • Qualcomm Snapdragon 625 octa-core, 2.0GHz
  • Qualcomm Snapdragon 625 octa-core, 2.0GHz
  • Qualcomm Snapdragon 625
  • Qualcomm Snapdragon 625
  • Samsung Exynos 7880 Octa-core 1.9 GHz Cortex-A53
  • Qualcomm Snapdragon 625 octa-core 2.0GHz
Built-in Memory
  • 4GB RAM
  • 4GB RAM
  • 3GB RAM
  • 4GB RAM
  • 3GB RAM
  • 3GB RAM
Display
  • 5.5-inch / 1,920 x 1,080 pixels (~401 ppi) / AMOLED
  • 5.5-inch / 1,920 x 1,080 pixels (~401 ppi) / IPS
  • 5.5-inch / 1,920 x 1,080 pixels / Super AMOLED
  • 5.5-inch Full HD (1,920 x 1,080 pixels resolution) AMOLED
  • 5.7-inch / 1,920 x 1,080 pixels (386 ppi) / Super AMOLED
  • Always-On Display
  • 5.5-inch / IPS / 1,920 x 1,080 pixels
Camera
  • Rear (main): 12-megapixel, f/1.7, TriTech+ AutoFocus, 4-axis OIS
  • Rear (secondary): 12-megapixel, f/2.6
  • Front: 13-megapixel, f/2.0
  • Rear: 16-megapixel, f/2.0, TriTech AutoFocus, 4-axis OIS
  • Front: 8-megapixel, f/2.0
  • Rear: 16-megapixel, f/2.0 aperture
  • Front: 5-megapixel, f/2.2 aperture
  • 16MP f/1.7 rear camera with dual PDAF, optical image stabilization, and Dual Tone LED flash
  • 16MP f/2.0 front-facing camera with Beautify 4.0
  • Rear: 16-megapixel, f/1.9, 27mm, LED flash
  • Front: 16-megapixel, f/1.9
  • Rear: 13-megapixel BSI CMOS camera with ultra-fast 0.1s PDAF technology
  • Front: 5-megapixel camera with f/2.0 aperture
Connectivity
  • Wi-Fi 802.11 a/b/g/n/ac, Bluetooth 4.2, USB 2.0 Type-C, Wi-Fi Direct
  • Wi-Fi 802.11 b/g/n/ac, Bluetooth 4.2, NFC, USB 2.0 Type-C, Wi-Fi Direct
  • Wi-Fi 802.11 a/g/b/n/ac, Bluetooth 4.0 LE + EDR, USB-C, 3.5mm audio
  • Bluetooth 4.1
  • Wi-Fi 802.11a/b/g/n/ac
  • Wi-Fi 802.11 a/b/g/n/ac (2.4 + 5GHz), 4G+ LTE Cat 9 (up to 450Mbps), Bluetooth 4.1, VHT80, MIMO (2x2), GPS, GLONASS, NFC, Screen Mirroring
  • Wi-Fi a/b/g/n/ac, Bluetooth 4.1, GPS, AGPS, GLONASS, BeiDou positioning, micro-USB 2.0
Storage Type
  • 64GB storage (expandable via microSD, up to 256GB)
  • 64GB storage (expandable via microSD to 2TB)
  • 32GB internal storage
  • 2TB MicroSD
  • 64GB internal storage
  • Expandable storage via microSD (up to 256GB)
  • 32GB internal storage
  • 256GB (MicroSD)
  • 32GB internal storage space
  • microSD support up to 128GB
Battery
  • 5,000 mAh
  • Reverse charging (1A)
  • 3,000 mAh
  • 3,510mAh
  • 3,010mAh with VOOC Flash Charge
  • 3,600mAh
  • 4,100mAh
Dimensions
  • 154.3 x 77 x 7.99 mm
  • 152.59 x 77.38 x 7.69 mm
  • 156.4 x 76.4 x 6.99mm
  • 153.0 x 74.3 x 6.58 mm
  • 156.8 x 77.6 x 7.9 mm
  • 151 x 76 x 8.4mm
Weight
  • 170g
  • 155g
  • 165g
  • 147g
  • 186g
  • 165g

 

Sunspider Javascript

SunSpider JavaScript measures the browsing performance of a device when processing JavaScript. It not only takes into consideration the underlying hardware performance, but also assesses how optimized a particular platform is at delivering a high-speed web browsing experience.

For your reference, the ASUS ZenFone Zoom S scored 29.674 for the JetStream benchmark – again, this is a new test where we're gathering test data, so we'll be a while more before we can transition. But as usual, the higher the score the better.

 

Quadrant

Quadrant evaluates a device's CPU, memory, I/O, and 3D graphics performance. Looks like the Zoom S is also on par with other Qualcomm Snapdragon 625 options on our list, so no surprises to be had here.

 

3DMark’s Ice Storm Unlimited

3DMark’s Ice Storm Unlimited test uses a mix of graphics and physics tests to measure hardware performance. The first test measures the GPU’s ability to process lots of vertices, while the second does the same thing with lots of pixels and post-processing effects. Finally, the physics test switches the load to the CPU to test its ability to process physics simulations, while keeping GPU load low. 

For your own reference, the ASUS ZenFone Zoom S scored 515 for the 3DMark Sling Shot Unlimited benchmark - we're still gathering companion results for this new benchmark, but as with 3DMark results, the higher the score, the better.

Overall, the ASUS ZenFone Zoom S performed reasonably and day-to-day use was rather painless with the minimal delays in between launching different apps. The phone was also very responsive in bringing up features like your preferred keyboard and moving into different menus as well.

 

Imaging performance

The ASUS ZenFone Zoom S’s headlining feature is the dual rear camera setup - they are both specced at 12 megapixels with very different purposes. The Main Camera uses a Sony IMX362 sensor (it has a 1/2.55-inch sensor size and 1.4mm pixel size), along with a six-element lens at f/1.7 aperture. It’s further assisted by 4-axis OIS (optical image stabilization), and ASUS TriTech+ - the latter is a series of different autofocus methods (Dual Phase Detection, Laser, Contrast Detection) that facilitates quick auto-focusing in most situations.

The accompanying Zoom Camera uses a Samsung 3M3 sensor (1/3.42-inch, 1.0mm pixel size) together with a five-element lens fixed at 59mm focal length (35mm equivalent) at f/2.6 aperture. This gives the Zoom Camera a fixed 2.3x optical "zoom" since the Main Camera has a fixed focal length of 25mm (35mm equivalent). We find that any sort of zooming in (between 2.3x to 12x magnification) is best on the Zoom Camera, as it combines both the optical 2.3x magnification along with digital zoom. Both camera's lenses are provided by a Taiwanese firm called Largan.

The phone's software automatically decides when it should trigger Zoom Camera.  We found that it's more likely to happen when you set the camera's Focus Mode to Continuous Auto Focus (it’s located under Focus & Exposure inside the default camera app's settings). It also helps when you start off by pointing at a faraway object. If you're shooting on Auto, simply tap the circle with "1.0x" within to quickly shift to 2.3x and 5.0x magnification. Pinching to zoom (up to 12x) works too. You can check if your Zoom Camera is active by blocking your rear lenses one at a time since the Zoom S uses only one rear camera at any given time.

Main Camera at 1.0x magnification on Auto. Click to view full-resolution image.
100% crop of above image.

The image quality on the Main Camera indicates that the ZenFone Zoom S might be ASUS’s best attempt at creating a camera-centric smartphone thus far. Color temperature might be a little warm, but it is good (for a phone camera) as it paid attention to things like detail, contrast handling, noise handling, and overall sharpness. You can easily make out the body text on the vodka bottle, the clumps of fur on the bear plushie, as well as the detailing on the War Machine figurine (center). If there's anything to pick on, it's the slight halo and jittering along the outline of the objects in the photo (around the vodka bottle, the deck of cards, the top of the bear’s head, etc.).

Zoom Camera at 2.3x default magnification on Auto. Click to view full-resolution image.
100% crop of above image.

The Zoom Camera on the other hand, leaves much to be desired, though functional with adequate color handling. It also lacks the OIS found on the main camera, and it's not as bright since it doesn't have the Main Camera's wide f/1.7 aperture as well. As a result, the image captured suffered from much noise and it affects all the details it should’ve captured. We find that the Zoom Camera is a better pick in situations where there’s plenty of sunlight to illuminate your subject. That said, being able to shoot from a further distance provides flexible positioning, although the person using the phone's Zoom Camera would benefit more if he/she can stabilize their zoomed shots.

As a whole, the Zoom S certainly did improve from the preceding ZenFone Zoom, but that’s only for the Main Camera. The second Zoom Camera could use a lot more work to truly destroy the competition. You can check out sample shots from the ZenFone 3 and the older ZenFone Zoom if you want to see the difference with your own eyes. The image quality (on the Main Camera only) is comparable to the ASUS ZenFone 3 Deluxe, which bodes well for the Zoom S thanks to its lower price point. The ZenFone Zoom S also has an intelligent system that combines optical zoom with digital zoom for the Zoom Camera, but we will go into the details in a separate piece.

ASUS is also serving up a host of manual controls in its camera app, with options for controlling things like exposure values, ISO, shutter speed, and the focal length.

Battery life

Our standard battery test for mobile phones includes the following parameters:

  • Looping a 720p video with screen brightness and volume at 100%
  • Wi-Fi and Bluetooth connectivity turned on
  • Constant data streaming through email and Twitter

The ASUS ZenFone Zoom S has a massive 5,000mAh battery capacity that seems impressive on paper. However, battery capacity isn’t everything, as proven by ASUS’s very own ZenFone 3 Max, ZenFone 3 Deluxe, and now, their Zoom S. We've also done our due diligence in getting our review set replaced, just to be sure what we've tested really holds true.

It's hard to believe the ZenFone Zoom S with nearly 70% more battery capacity than the ZenFone 3 only manages to meet the latter's battery-uptime. Add to the similarities between both devices and the fact that the newer Zoom S uses a more power efficient AMOLED screen, the battery life testing outcome is really bizarre for the Zoom S. While it's not completely unexpected since the Xiaomi Redmi Note 4 has a slightly smaller 4,100mAh capacity, and it reported a proportionately lower lifespan than the 5,000mAh ZenFone Zoom S.

While we were hoping to get some phenomenal battery uptime results somewhat like the Moto Z Play or even better, we have to admit that over 700 minutes of battery life is still a very reasonable figure from a usability perspective. The problem is likely related to the optimization done on the device and how all the various components within the device come into play that unfortunately give the ZenFone Zoom S poor battery efficiency. Your actual mileage will vary from our battery drain scenario as real-world usage varies greatly from one user to another.

Or did ASUS actually get their battery specs wrong and it's only 3,000mAh in capacity? While the outcome certainly feels like such, it's just an interesting thought.

 

Conclusion

The ASUS ZenFone Zoom S isn't exactly special or new given its design and its choice of features. We’ve already seen how it’s possible to bring a dual rear camera setup to a mid-range device from two years ago. For ASUS, their take of this feature is coupled with a premium-looking body, a good mainstream processor and a Main Camera that’s far better than its predecessor; it is also within the conventional price range for similarly classed/featured phones. Unfortunately, the S$678 ZenFone Zoom Sunder delivers for its price tier as consumers would expect more than just average capabilities.

The higher price tag is supposedly justified by adding hardware features such as the Zoom Camera functionality and 5,000mAh battery. Both are pivotal reasons for paying more for a ZenFone Zoom S over the ZenFone 3, yet those are the exact features that fall short of our expectations from extended testing with with the device.

The ZenFone 3 base model (S$498) did such a great job at its price point, it's inevitable that every variant that follows along (like our ZenFone Zoom S here) will be measured against its parent handset at a performance-per-dollar metric. Do you pay an extra S$180 for a phone that's designed different with dual rear cameras and a 5,000mAh battery (both of which don't quite deliver in our testing), or do you save that money and get a similarly powerful device from the same maker without an extra camera and 'more battery capacity'? The choice isn't as clear when you don't quite know how the phone actually performs like we've found out, and much less so if you aren't chasing for the latest and greatest purchase within a budget you can spare.

On its own the ZenFone Zoom S holds itself together just fine as it marks the base level expectations from the phone's design, feel, handling, general performance for a Snapdragon 625-powered device and good imaging out of the Main Camera. 

However fierce competition (even from their own product line) takes away any glint that the ZenFone Zoom S has to offer. The pressure also comes from other competitors who have since introduced mobile phones with Qualcomm Snapdragon 625 processors at various price points – the Xiaomi Redmi Note 4 is for the wallet-conscious bargain hunters; the Moto Z Play provides premium features and user experience with a price tag to match; the similarly-priced Oppo R9s already filled the niche for a pretty, practical phone with a slightly unique rear camera sensor. This makes it difficult to recommend the Zoom S over the ZenFone 3 or its direct rivals when its unique features don't shine and the other aspects are simply on par with the rest.