In terms of battery life, Oppo F9 performs admirably well. It comes with a 3,500 mAh battery which is plenty of juice for device to comfortably last all day. Unfortunately, Oppo's software doesn't make it easy to gauge screen-on time statistics as on other Android phones. Oppo F9 managed to run for 13 hours, 12 minutes in my HD video loop test. That's thanks to low-power LTPS screen, Helio P60 SoC's efficiency, and optimizations built into ColorOS. With ordinary use including some gaming, video streaming and plenty of time spent online, I easily sailed through a full day and didn't have to worry about battery level till next morning.
Oppo F9 is also very quick to recharge with Oppo's VOOC fast charging. This is one of the fastest charging methods available which you may be more familiar with as Dash Charge on OnePlus devices. VOOC flash charging is supposed to charge phone four times as fast as existing 5V/1A charging systems. If that sounds like a recipe for a Samsung Note 7-style inferno, Oppo claims you have nothing to worry about, with VOOC offering five layers of protection and a low operating temperature. VOOC charger is enormous and will be a pain to carry around, but it works brilliantly. A 10-minute charge from zero took phone up to 19 percent, and I was able to get to nearly 75 percent in just 40 minutes, which is really impressive.
Overall, I think this is the best aspect about this phone, together with its display. A major selling point for this new arrival by Oppo.
This is a part where Oppo F9 feels like an upgrade over Oppo F7. Instead of just a single rear shooter, it now also has a secondary sensor for bokeh effects. Dual camera setup at back consists of 16 MP main shooter with an f/1.8 aperture and 2 MP depth sensor with an f/2.4 aperture. It comes with your usual camera features like HDR, Time-Lapse, Slow motion, Panorama, and Manual mode. Portrait mode has 3D lighting effects found on Oppo Find X as well as AR stickers, Super Vivid mode, and AI Beauty Technology 2.1.
Image quality is good but not at same level to, let's say, Oppo Find X. It has AI scene recognition as well and was able to easily recognize scenes like food, landscape, and pets. Photos produced by rear and front cameras are sharp with accurate colors and nice contrast. It can handle dim conditions like indoors but not so much in low light as details are smudgy and noise starts to become more evident. At night, there was quite a bit of focus lag together with shots coming out with murky details and a lot of blurring when dealing with even slightly moving objects. Most of sample photos looked fine on phone's screen but weren't suitable for use at full size.
Oppo's camera app is somewhat like the one on iOS, just with a lot more going on. Main mode ribbon at the bottom includes Timelapse, Slo-mo, Portrait, Sticker, Panorama, and Expert modes along with standard Photo and Video. Portrait mode was pretty fussy about prompting me to move closer to or farther away from subjects. There are also "lighting effects" which are little more than mild filters. The Slow-mo and Timelapse video modes didn't have any options at all for us to tweak, not even resolution. You get Google Lens integration in standard Photo mode, along with beautification, filters, and a choice of aspect ratios.
There's a 25 MP selfie camera with f/2.0 aperture. Front camera is usually one of Oppo's biggest highlights, but in this case, I wasn't terribly impressed. Faces looked sharp, but background details were completely lost. Depth effect made backgrounds look a little cartoony, which might not be a bad thing, and edge detection was fairly good. Selfies taken at night were grainy and I wouldn't want to show them off on my social media, to be honest. You can simulate a depth effect with the front camera, but it isn't very natural. Beautification mode is set to 'AI' by default, and I found it to be way too aggressive, making me look almost animated. Selfies taken indoors weren't very impressive while in daylight, I found camera app to be responsive, locking focus quickly. Shots looked crisp, with good colors and adequate detail. In portrait mode, phone often took a few moments to settle difference between foreground and background objects, but I was able to see effect on screen and decide when to capture shots. With video, you have a choice between 720p and 1080p for with rear cameras, and there are no settings to play with. I saw a lot of focus shifting, and lack of stabilization was evident throughout shots that I took.
Phone's camera doesn't come with any kind of stabilization and overall, I would say that I am somewhat disappointed with Oppo F9 camera capabilities.
Frankly, my least favorite part about Oppo F9 is its software experience. Oppo F9 runs Android 8.1 Oreo with ColorOS, Oppo's overbearing skin. ColorOS not only changes much of aesthetics of stock Android but tries to emulate iOS as much as possible. Appearance of icons, wallpapers, and features feel very similar to ones on Apple devices. Some features are pretty unintuitive compared to how stock Android handles them. Notifications can simply be swiped away to dismiss them on stock Android, but not on ColorOS. Instead, you have to swipe notification to right and tap on trash can icon to dismiss it. This method feels clunky and makes it difficult to clear away notifications quickly.
Inside Settings, you will see more of ColorOS with features like Assistive Ball, Smart Sidebar where you can quickly access apps and tools, Gesture controls, Smart Driving, Smart Assistant, Clone Apps, Game Space, and App Split Screen. It also has security features like Find My Device, Payment Protection, App Lock, Kids Space, and Private Safe, to name a few. There's a fair bit of bloatware as well, including UC Browser and Amazon Shopping. I was prompted to install more during initial setup process, through an Oppo AppStore, and also through a 'Hot Apps' panel on home screen that looks deceptively like an ordinary system folder. Oroaming is an app that claims to let users buy cheap roaming plans in multiple countries without needing a local SIM, but how this works is never really explained. Theme Store has quite a few free themes and wallpapers. Icon packs provide colorful visuals and wallpapers are actually quite nice to look at.
Settings app has a number of options to discover. You can swap around on-screen navigation buttons or disable them and use gestures instead. There are assorted gestures and shortcuts. A Smart Driving mode can block notifications and calls, an interesting privacy feature is that you can choose to spoof your call history, contacts, messages and events if apps try to access them. Face recognition is supported but you have to wake your phone and then swipe upwards to trigger front camera, which is an annoying extra step.
At the end of day, it's still a very annoying OS which Oppo needs to revisit and improve to attract larger audiences towards their phones, including Oppo F9.
Oppo F9 is available in selected regions like Vietnam, Philippines, Pakistan and India. In Vietnam, it is priced at around $330. It comes in three different colors: Sunrise Red, Twilight Blue and Starry Purple.
Oppo F9 feels more like refinements of Oppo F7 than a successor, but that is not to say that they are negligible. New waterdrop screen, prettier design, increased RAM, updated OS, dual rear cameras, and a larger battery with VOOC Flash Charge, are very welcome improvements. My biggest concern is whether buyers will be willing to prioritize this design over performance. Oppo F9 delivers great battery life and a reasonable overall usage experience, but it isn't the best you can get for your money by a long shot. I would have at least liked a metal body, weather proofing, and basic video stabilization at this price. Better cameras would also have made me more forgiving. Most people can live quite happily with 4GB of RAM rather than 6GB, and if you're most concerned about gaming performance for example, you should be looking elsewhere anyway. Also, while base variant of Xiaomi Pocophone F1 is a clear outlier in this price segment, I can't ignore how much value it offers as compared to Oppo F9.
I personally believe that biggest hurdle for Oppo and Oppo F9 is competition in mid-range segment. It was already tough before, with all usual players, but a few brands have really been turning heads as of late. It'll be interesting to see how well this phone does in market, and how other brands like Honor and Xiaomi responds to Oppo F9.