Asus Zenfone Zoom Review: Taking a Closer Look at an Optical Zoom Phone

By Alex Cranz on at

Your phone has been lying to you. Every time you zoom in to catch that perfect shot of that expensive gourmet burger you’re not actually zooming in. The software in your phone is really just cropping the image and blowing it up. To actually zoom your phone would need an optical lens, but the theory is that optical lenses tend to be too big, too bulky, and too delicate for a phone. The Asus Zenfone Zoom puts that theory to the test – much like the Samsung Galaxy S5 Zoom – by cramming a 3x optical zoom lens into a phone not much thicker than Asus’s budget-friendly Zenfone 2.

It feels heavier than the Zenfone 2 too, and the Samsung S6, and the iPhone 6s Plus. The heft is more reminiscent of a quality point and shoot or bridge camera than a modern mobile phone. The phone doesn’t slide into the back pocket as smoothly as my iPhone, but it’s slim enough that I haven’t had a single issue yanking it out of my purse to take “artful” pictures of train platforms.

Asus Zenfone Zoom Review: The First Smartphone With A Real Zoom LensThis is not art. This is contrast and desaturation being cranked to the max.

If you’ve ever seen a hardcore camera phone, like the 41-megapixel Nokia Lumia 1020, than the back of the Zenfone Zoom will be familiar. The bulging black plastic disk housing the lens apparatus and taking up nearly half of the back of the phone seems to be ubiquitous in all serious camera phones. The rest of the back of this particularly serious camera phone is covered in leather—like the grip of a traditional camera.

Also like a traditional camera, the lens in the Zenfone Zoom, you know, zooms. It all happens inside the housing and you’ll need a torch and excellent vision to watch it, but once you catch the smooth working of the Hoya lens, don’t be surprised if you spend a few minutes zooming back and forth and marvelling at the mechanism — because an optical zoom lens in a smartphone is still a novel, not-widely-employed feature. It should, theoretically, take much better photos than the lousy digital zoom featured in every other smartphone on the market.

Asus Zenfone Zoom Review: The First Smartphone With A Real Zoom LensOn the left the Zenfone Zoom—zoomed, cropped, and blown up. On the right the iPhone 6 just...zoomed.

When traditional smartphone cameras “zoom” they can lead to wickedly ugly pictures. Details disappear beneath a barrage of digital artefacts. Bricks merge into one another. Leaves turn into amorphous blobs on the tree branches. Fine details like windows, turrets, and even water towers simply vanish.

That’s not the case with the Zenfone Zoom. Even cropped, like above, the image is sharp and the colours are vibrant. The optical zoom lens works exactly as intended.

The bokeh on the other hand...

Asus Zenfone Zoom Review: The First Smartphone With A Real Zoom LensHandsome and sharp dog. Ugly and fuzzy background.

Bokeh refers to the blur-over objects that are out of focus in a photo. It should be artistic and attractive. The Zenfone Zoom’s bokeh is neither. In the case of the photo above, the old dog is in focus and sharp. You can make out every white hair interspersed among the black. But the background just a metre behind him looks bizarrely, almost artificially, blurry. It’s less bokeh and more like someone smeared some grease all over the lens.

At least the dog is in focus. Because the Zenfone Zoom has an optical lens it can do contrast focusing like a traditional camera. It also features laser focusing like the LG G4. When the two methods of focusing work, they work well and they work fast, but I ran into an issue where both methods of focusing would just....stop after heavy use. Restarting the camera app solved the problem, but if you’re planning on doing a whole photoshoot with your smartphone you should learn how to restart an app in Lollipop first.

Asus Zenfone Zoom Review: The First Smartphone With A Real Zoom LensJust three of the many screens full of options available in the camera app.

You should also take some time to learn the camera app. The Zenfone Zoom’s app features the best camera control available out of the box in a smartphone to date. You can control every aspect of the camera short of the aperture. ISO, white balance, exposure value, and most notably, shutter speed, are all at your command — and if those words make absolutely no sense to you, then maybe the Zenfone Zoom is not the device you are looking for.

Speaking of the phone: camera aside, it’s a decent one. The Zenfone Zone isn’t gratingly slow and the skin that Asus smacks on Lollipop isn’t offensive. Some of the additional apps are even useful. Power & Boost shuts off rarely used processes to save battery life and Power Saver offers presets that can add up to 50 hours of additional standby time to the battery. The bloatware is kept to a minimum too: there’s a messenger app for the off chance you have a bunch of friends with Asus phones, and two different tech support apps that led me to wonder what the hell people are doing with their phones that they need that much tech support on one of the home screens.

Asus Zenfone Zoom Review: The First Smartphone With A Real Zoom Lens

There’s also an app, Splendid, to control the color output of the 1080p IPS display. I wasn’t impressed with it. The Vivid setting turns everything so bright it borders on fluorescent, the custom setting gives you no real control over the display, and there isn’t a single setting to control the gamma — which is way too high. This leads to the blacks being too saturated and the whites too bright. When I took a picture of my dog frolicking in the snow he appeared to be an amorphous blob frolicking on the surface of a white hot star. He came out much more dog-like when I loaded the same photo onto my computer.

Oversaturated display aside, the Asus Zenfone Zoom (which can be found online unlocked for prices ranging between £335 and £375) is easily the best “serious photographer” smartphone currently available. Proper optics and a real zoom lens feel like absolute game changers when it comes to smartphone photography. There a quality to the Zenfone Zoom’s photos that the competition just can’t match. If they manage to fix the issue with the ugly bokeh, the Zenfone Zoom could easily replace any point-and-shoot you keep in you bag.

Asus Zenfone Zoom Review: The First Smartphone With A Real Zoom Lens



  • Optical zoom lens means unprecedented control
  • Wicked sharp images, but ugly bokeh
  • Hefty size is reminiscent of a regular camera
  • High gamma means the blacks are too black
  • Also a phone