Oppo A91 is the new mid-range smartphone of the Chinese brand, which offers a large AMOLED display, quadruple camera and a great autonomy. Some aspects, however, did not fully convince us. But no spoilers: let's discover this Oppo A91 in our review.
Oppo A91 review: a great display
The first thing we notice as we pick up the phone is the polycarbonate back cover that replaces the skin or glass present in the higher-end Oppo models. The lack of premium materials, however, does not change the feeling of the smartphone: to the touch it is really pleasant and compact, feeling also increased by very small edges, with a screen-to-surface ratio of 90.7%.
The display is a FullHD+ AMOLED of 6.4" with resolution 2400 × 1080 pixels, which can be seen well in all lighting conditions. On the upper part of the screen, to keep the bezels very thin, a teardrop notch has been inserted for the front camera. The capsule is inserted along the upper edge, while the fingerprint sensor is integrated under the display and it is very accurate.
Along the frame of the smartphone we find on the left the volume rocker and the trolley to insert the SIM and the microSD expansion, the power button on the right. On the underside, however, there is a surviving 3,5 mm jack for headphones, in addition to the USB-C input, the speaker and the microphone.
On the back, inserted in the rear body, there is the photographic compartment composed of 4 sensors placed vertically.
What we find under the body
Oppo A91 has a well-stocked data sheet, with ben 8GB of RAM memory, which will never force you to limit the applications open in the background, e 128GB of storage, expandable via microSD card. The main engine that moves the smartphone is composed of a Mediatek CPU and a Mali G72 GPU. The choice of inserting a Mediatek processor can be more or less shared, but in daily use it behaves well and we have not noticed any obstacles.
Reception is excellent and the Wi-Fi connection is very stable, but we would have liked to see a Bluetooth 5.0 while we have to settle for version 4.2.
Autonomy is one of the strong points of Oppo A91: the battery that powers everything is from 4025mAh and allows you to cover a day of stress use very well, arriving in the evening with as much as 25% of residual charge. Furthermore, thanks to the support of VOOC 3.0 fast charge at 20W you can recharge your smartphone on the fly in emergency situations. In short, you can safely leave your powerbank at home.
The thing that convinced us less was the decision to implement an older generation ColorOS from the software side, currently in fact the device is updated to version 6.1.2. With the more recent ColorOS 7, you could have enjoyed all the additional features introduced in the last period.
A camera without infamy and without praise
The smartphone of the Chinese brand is equipped with a quad-camera. The main sensor is 48MP with aperture f / 1.79, followed by one wide-angle camera of 8MP f / 2.25, un depth sensor it's a lente B / W, both from 2MP. The front camera, on the other hand, is 16MP.
- shots are discreet and the colors are well balanced, especially in daylight, with good management of contrast and white. Macros are detailed and focusing is very fast. Instead, it lacks a bit on night shots, despite there is a specially dedicated mode, in fact the results are not very detailed and there is a lot of noise. Perhaps in the next software updates the optimization will be improved in order to implement a better management of low light shots.
As for the videos, however, Oppo A91 is able to shoot with maximum resolution of 1080p at 30fps with the rear camera and 720p / 30fps with the front one.
Oppo A91: technical sheet
dimensions: 160,2 73,3 mm x 7,9x
Weight: 172 g
Display: 6,4″ AMOLED fullHD+ – 2400 x 1080 pixel
CPU: Mediatek MT6771V
GPU: Mali G72
RAM: 8 GB
Memory: 128 GB
Network: dual SIM
Connectivity: Wi-fi 2.4/5GHz 802.11 a/b/g/n/ac, Bluetooth 4.2, USB-C, GPS
Battery: 4025 mAh
Rear camera: 48 MP + 8 MP + 2 MP + 2 MP
Front Camera: 16 MP
Videos: 1080 @30fps
Operating system: Android 9 with ColorOS 6.1.2
Oppo A91 review: buy it or not
Oppo A91 is a mid-range smartphone initially released around € 330 and that it is currently under € 300. Overall it is a good device, without jamming and offering average performance. The AMOLED display convinces both for the resolution and for the high brightness and the available memory will never run out thanks to 128GB plus microSD. Oppo A91 is very balanced, even if we would like to underline some shortcomings not present in other devices placed in the same price range.
Oppo A91
For 
- Great display
- Excellent autonomy
- Quick charge
Cons 
- Camera in night conditions
- Bluetooth 4.2
- ColorOS 6.1.2
