Asus Zenfone 9 review

No tele, but a gimbal-mounted main camera and AF all around

The Zenfone 9 improves on the camera system of the previous model with a new primary unit, while keeping the ultrawide and the selfie cameras, both of which the Zenfone 8 had already dialed in pretty nicely.

The new primary camera features a 1/1.56" Sony IMX 766 sensor - a Quad Bayer design with 1.0µm pixels, 50 million of them. It uses the 2x2 OCL method for its phase detection autofocusing, which makes it sensitive to changes in detail in both principal directions as opposed to the usual left/right only capability of generic dual pixel autofocusing - so you should be able to get faster and more accurate autofocus in more shooting conditions.

The lens in front of that sensor has a 24mm equivalent focal length and an f/1.9 aperture.

This whole ensemble is mounted on a gimbal too. What Asus's press materials specify as 6-axis stabilization is capable of providing compensation for up to 3 degrees of shake, compared to the 1 degree that conventional OIS can do.

It's worth pointing out that, going by the specs, the setup looks just like the one found on the vivo X70 Pro though vivo lists the lens aperture at f/1.8.

The Zenfone 9's ultrawide camera is the same as the 8's. That means a 12MP Sony IMX363 1/2.55" sensor with 1.4µm pixels and a 14mm f/2.2 lens. It's got dual-pixel PDAF and it can also do close-up photography from as close as 4cm.

Over on the front, it's another tried-and-tested setup lifted off the Zenfone 8. A 12MP Sony IMX663 1/2.93" sensor with 1.22µm pixels and dual pixel PDAF sits behind a 28mm f/2.45 lens.

The camera app has been redesigned slightly, though basic operation remains largely the same as before and the same as on any other camera app. The new feature is the contextual options pane you can pull out by tapping on the little arrow at the far end of the viewfinder or by swiping down in the viewfinder itself. In basic Photo mode, that's where you'll find the flash modes, aspect ratio and HDR settings, while in Video you have the resolution, frame rate and stabilization modes.

The full-res mode for the main camera is found under the 'Camera resolution' menu item in the app settings, where you also get the same aspect options as in the slide-out pane in the viewfinder - perhaps having the 50MP mode there as well is logical?

There's a nice Pro mode too, with manual control over exposure parameters, white balance and focusing. A live histogram is available and focus peaking shows up when you try to focus manually. A need auto bracketing feature can do three shots with different exposures 0.5 to 2EV apart.

Camera UI

Daylight image quality

Daylight samples from the Zenfone 9's main camera have great global properties. Colors have plenty of pop without going into oversaturation while white balance is consistently accurate. Contrast is high and dynamic range is very good.

On a pixel-level, we're seeing good detail, essentially the same as you'd get from any current 12-ish MP camera. What we're not so keen on is the way detail is presented - it can have a very processed and artificial rendition, particularly with organic textures like flowers and foliage. It's not the end of the world, it's just not a very pleasing look.

Daylight samples, main camera (1x)

The ultrawide camera is more natural in the way it renders detail and it's one of the better ultrawides in good light despite a bit of extra noise in the shadows. From afar, there' little to complain - dynamic range is solid, colors are likeable, and the close-focusing capability means you can shoot nearby subjects too.

Daylight samples, ultrawide camera (0.6x)

Daylight samples, ultrawide camera (0.6x), closeups

Circling back to the main camera for 2x zoom-in action, we're looking at some very decent shots, particularly if the subject matter is mostly straight lines. More random textures don't quite have the same detail that a dedicated 2x camera can capture, but overall it's not a bad performance here.

Daylight samples, main camera (2x zoom)

Opting for the full-resolution 50MP mode will deny you the benefits of HDR, without delivering tangible real-world detail benefits. We did see improved detail in our studio charts at close range and under controlled lighting, so there's that.

Daylight samples, main camera (1x), 50MP

Low-light image quality

There's auto Night mode detection on the Zenfone 9, a pre-enabled toggle in settings, which you can disable if you wish. We did turn it off to establish a baseline but perhaps you shouldn't. The images we got that way, even on the main camera, tend to be underexposed and with very limited dynamic range, unless you find a particularly well lit scene.

Low-light samples, main camera (1x), auto Night mode OFF

Night mode addresses that and introduces dramatic improvements to tonal development. It brights out the shadows and tones down the highlights making for a vastly more likeable exposure. That also reveals detail at both extremes which you couldn't see with Night mode off. There's a hike in sharpening, naturally, which can make certain detail look plasticky, but overall this a much better rendition of low-light scenes.

Low-light samples, main camera (1x), dedicated Night mode

Which brings us back to that auto Night mode toggle in settings. When it does engage, it will deliver essentially the same images as the ones you get in the dedicated Night mode - it's not a half-there approach. The thing is, though, it may not kick in every time you'd want it to - it didn't in scenes 2 to 5.

Having said that, you get a clear indication in the viewfinder with a crescent and a seconds indicator when it does engage (as you do in the Night mode itself), so it's not doing things behind your back.

Not that its Night mode action can remain unnoticed - the usual duration of Night mode shots on the main camera is 3s. We've been spoiled by speedier and fully-functional Night modes recently and this one can feel like a drag.

Low-light samples, main camera (1x), auto Night mode

With the auto Night mode detection off, the ultrawide can suffer from similar exposure woes as the main one and particularly dimly lit scenes will end up underexposed.

Low-light samples, ultrawide camera (0.6x), auto Night mode OFF

As expected, Night mode fixes this and brings out color and detail from shadows and highlights alike. Images do get oversharpened, but also actually sharper too and noise is reduced. The process can take longer on the ultrawide, with 4s being the usual time required.

Low-light samples, ultrawide camera (0.5x), dedicated Night mode

When it comes to the auto Night mode, it's somewhat of a similar story on the ultrawide as we observed on the main camera. 3 out of the same 4 scenes that failed to trigger Night mode on the primary unit didn't do it here either (samples 3 to 5 below).

Low-light samples, ultrawide camera (0.5x), auto Night mode

Zoomed in shots with the auto Night mode off generally turn out soft and noisy when its especially dark. That said, we did get some keepers in certain scenes - 4, 5 and 7 look decent, we reckon.

Low-light samples, main camera (2x), auto Night mode OFF

While there's no 2x shortcut in Night mode, pinch zooming can get you there. It significantly improved the sharpness of the photos in the other 4 scenes, while not affecting the keepers in a negative way, so you'd still generally be better off with the Night mode processing in action.

Low-light samples, main camera (2x), dedicated Night mode

Once you're done with the real world samples, head over to our Photo compare tool to see how the Asus Zenfone 9 stacks up against the competition.

Asus Zenfone 9 against the Galaxy S22 and the iPhone 13 in our Photo compare tool

Portrait mode

The Zenfone 9's Portrait mode shoots at a slightly zoomed in 'focal length' compared to its main camera's native output - we're eyeballing it at a 35mm equivalent. That has a most welcome effect on shooting distance and perspective - you're not in your subject's face and facial proportions are more flattering than what the native 24-ish mm equivalent can give you for the same framing. The flipside is that absolute sharpness suffers a bit, but the drop in quality isn't huge, plus your subject may appreciate not having every single imperfection visible.

The default simulated aperture level is f/11, which sounds like it won't give you any background blur, but we actually quite like the results - it gives the necessary separation between subject and background without screaming 'smartphone portrait mode' at you. You can change the simulated aperture all the way to f/0.95, and you can play around with the value post-shot too, though these extreme values do achieve the screamingly artificial look mentioned above.

Subject detection is quite proficient too, with the conservative blur level helping to mask whatever little imperfections there might be.

Portrait mode samples

Selfies

The Zenfone 9 is capable of some pretty great selfies. Dynamic range is nice and wide and no backlit scene will be a problem while the nicely saturated colors make for a pleasing look. Detail is excellent too, though at anything other than base ISO (25) noise in the shadows becomes quite apparent. The autofocusing capability with face detection does ensure your mug will be sharp regardless of the numerical representation of 'arm's length' in your particular case.

Selfie samples

The selfie portraits are about as great as the ones from the main camera. Subject detection is solid and the conservative default blur level makes for a nicely natural look.

Selfie samples, Portrait mode

Video recording

The Asus Zenfone 9 can record video all the way up to 8K24 with its main camera and both the main and the ultrawide can do 4K30 and 4K60. The selfie camera, on the other hand, can do 4K30 and 1080p up to 60fps. As is the norm, you can choose between the h.264 codec (the one used by default) and the more efficient h.265. Stabilization is available in all modes on all cameras and can be switched off if you have other means of supporting the phone.

8K out of the main camera (130Mbps bit rate) is nothing special. Detail is about average for smartphone 8K, which is to say pretty meh on a pixel level - the Mi 11 Ultra remains vastly superior in this respect.

The 4K30 clips (57-61Mbps) are nicely detailed and noise-free. The high contrast and vivid colors give them a pleasing pop that we enjoy in our videos. The 4K60 mode (75-93Mbps) comes with a minor sharpness penalty, but is otherwise the same.

The ultrawide camera's footage is among the better ones you can get too. Sharp and detailed in 4K30 mode (again, ever so slightly less so at 60fps), it offers the same expressive look as the main camera with plenty of contrast and lively color output.

There's no zoom camera on the Zenfone 9 and the 2x toggle found in stills isn't available in the video viewfinder. You can still pinch to zoom to 2x (and beyond, if you must), but the results won't be great if you look at them from up close.

In low-light situations, the main camera holds up decently well - it's not winning contests for dynamic range or sharpness, but areas of more balanced lighting have good detail and colors are generally well preserved.

The ultrawide camera's clips are softer and noisier, but still very much usable in a pinch.

Stabilization is spectacular on the main camera, leaving next to no trace of walking shake, smooth pans and rock-solid footage when just pointing the phone in one direction. That applies to both the 30fps and 60fps clips too.

The ultrawide is a similarly competent performer even though it's missing the gimbal of the main camera.

Here's a glimpse of how the Asus Zenfone 9 compares to rivals in our Video compare tool. Head over there for the complete picture.

Asus Zenfone 9 against the Galaxy S22 and the iPhone 13 in our Video compare tool