Samsung Galaxy A51 Factory Unlocked Cell Phone | 128GB of Storage | Long Lasting Battery | Single SIM | GSM or CDMA Compatible | US Version | Black
Appearance and usability
The Samsung Galaxy A51 is still not a large, elegant, thin and light smartphone. Although it is already heavier than the A41 by as much as 20 grams, it can still be considered a miniature mobile device. At least, with its size and well-thought-out shape, the Galaxy A51 case is comfortably held in your hand.
The design is calm, without gradient iridescence, although with a gloss. Everything is designed in a single color scheme, decorated with a geometric strict discreet pattern. The surfaces are mirrored, but the device does not sparkle in the sun, like a Christmas tree toy.
Everything here is plastic: both the frame and the back cover. However, all together, it looks quite stylish and not cheap at all.
Samsung Galaxy A51 does not slip out of your hands, its glossy surfaces remain fingerprints, but they are easily erased — the coating is reliable and practical. In general, the smartphone is designed in an ideal ratio of dimensions, weight and screen size, so that it is both comfortable to hold and comfortable to work with a large screen.
The design of the unit with cameras and flashes on the back side is made in the same style for the entire line with a protruding black rectangle, regardless of the overall color of the case.
For the front camera, a small round cutout is made in the screen. Curiously, in some neighboring models in the family, for example, A41, the camera is embedded in a teardrop-shaped cutout, and here it is a hole, but also in the middle, and not on the side. The camera is single. For some reason, the LED indicator in the smartphone was not installed, but it’s a pity.
The side buttons do not differ tactically, but they stick out noticeably from the case. The buttons are not very large, but they have a distinct elastic and distinct stroke, there are no complaints.
The fingerprint scanner is sub-screen. The sensor is not ultrasonic, but optical. This is worse, but it works more or less tolerably. Although with the classic capacitive, of course, it can not be compared in terms of response speed.
The card slot is designed for two Nano-SIM cards and a microSD memory card, with a triple slot. Hot swapping is supported.
On the upper end of the elements, only an additional speaker can be observed.
In the lower end, there is a speaker, a conversation microphone, a USB Type-C connector and a 3.5 mm audio output for headphones.
The smartphone is available in several colors, including black, white, blue and pink. The smartphone case did not receive full protection from dust and moisture.
The Samsung Galaxy A51 smartphone is equipped with a Super AMOLED display with a diagonal of 6.5 inches and a resolution of 2400×1080. It is covered with Corning Gorilla Glass 3. The physical dimensions of the screen are 67×150 mm, the aspect ratio is 20:9, the point density is 405 ppi. The width of the frame around the screen is 3 mm from the sides, 4 mm from the top and 5 mm from the bottom. The screen does not support a refresh rate of either 90 Hz or 120 Hz. There is no choice for the screen resolution either.
The front surface of the screen is made in the form of a glass plate with a mirror-smooth surface, resistant to scratches. Judging by the reflection of objects, the anti-glare properties of the screen are no worse than those of the Google Nexus 7 (2013) screen (hereinafter simply Nexus 7). For clarity, here is a photo in which the white surface is reflected in the turned-off screens (on the left — the Nexus 7, on the right-the Samsung Galaxy A51, then they can be distinguished by size):
The screen of the Samsung Galaxy A51 is noticeably darker (the brightness of the photos is 109 versus 114 for the Nexus 7) and does not have a pronounced shade. The doubling of reflected objects in the screen of the Samsung Galaxy A51 is very weak, this indicates that there is no air gap between the layers of the screen. Due to the smaller number of borders (such as glass/air) with very different refractive indices, screens without an air gap look better in conditions of intense external illumination, but their repair in the case of cracked external glass is much more expensive, since you have to change the entire screen. On the outer surface of the Samsung Galaxy A51 screen, there is a special oleophobic (fat-repellent) coating (effective, better than that of the Nexus 7), so finger marks are removed much easier, and appear at a lower speed than in the case of ordinary glass.
When displaying the white field in full screen and manually controlling the brightness, its maximum value was only 360 cd / m2 under normal conditions, but in very bright light it rises to 560 cd / m2. You also need to take into account the fact that in this case, the smaller the white area on the screen, the lighter it is, that is, the actual maximum brightness of the white areas will almost always be higher than the specified value. As a result, the readability of the screen during the day in the sun should be at an acceptable level, and a dark theme not only saves battery power, but also contributes to better legibility of information on the screen in high light conditions. The minimum value is 1.7 cd / m2, which means that the reduced brightness level allows you to use the device even in complete darkness without any problems. The brightness is automatically adjusted by the light sensor (it is located under the screen close to the top edge and to the right of the center). In automatic mode, when the ambient light conditions change, the screen brightness both increases and decreases. The operation of this function depends on the position of the brightness slider: the user can use it to try to set the desired brightness level in the current conditions. If you leave everything by default, then in complete darkness, the auto-brightness function reduces the brightness to 8 cd/m2 (a little dark), in an office lit by artificial light (about 550 lux) sets it to 110 cd/m2 (normal), and conditionally under direct sunlight increases it to 560 cd/m2 (to the maximum, and it is necessary). The result did not quite suit us, so in complete darkness we slightly increased the brightness, resulting in the following values for the three conditions mentioned above: 15, 120-150 and 560 cd/m2 (the perfect combination). It turns out that the auto-brightness adjustment function works adequately and to some extent allows the user to adjust their work to individual requirements.
At any brightness level, there is a significant modulation with a frequency of about 60 or 240 Hz.
The screen is characterized by excellent viewing angles. True, the white color, when deviated even at small angles, takes on a light pink or blue-green hue, but the black color remains just black at any angles. It is so black that the contrast parameter is not applicable in this case. For comparison, here are photos in which the screens of the Samsung Galaxy A51 and the second participant of the comparison display the same images, while the brightness of the screens on the white field is initially set to about 200 cd/m2, and the color balance on the camera is forcibly switched to 6500 K.
The color reproduction is good, the colors are moderately saturated, and the color balance of the screens is slightly different. Recall that the photo can not serve as a reliable source of information about the quality of color reproduction and is provided only for conditional visual illustration. In particular, the pronounced reddish hue of the white and gray fields present in the photos of the Samsung Galaxy A51 screen is visually absent when viewed perpendicular, which is confirmed by hardware tests using a spectrophotometer. The reason is that the spectral sensitivity of the camera matrix does not exactly coincide with this characteristic of human vision.
The Samsung Galaxy A51 has only two full — fledged modules for shooting-normal and wide-angle, without a telephoto lens and optical zoom. The third and fourth modules are installed with low characteristics as a depth sensor of the scene and a separate camera for macro photography.
The main module has a lens with an f/2.0 aperture and a 48 Mp sensor (EFR 26 mm, 1/2. 0″, 0.8 microns). Here everything is exactly the same as in the younger A41. There is a PDAF phase autofocus, no stabilization. A medium-brightness flash. The camera can shoot in full resolution or in 12 MP with the function of virtual combining 4 pixels into 1.
However, it is difficult to immediately guess how to switch to the shooting mode in full resolution: the resolution, for some reason, is hidden under the icon for the aspect ratio of the frame, and not in the general settings. As a result, if you do not read the instructions, you may not even know that your smartphone can shoot in all its 48 MP.
A separate module for macro photography can shoot at a distance of 4 cm from the object. It is clear that with a small depth of field, not all details fall into the sharpness zone, but still sometimes you can achieve interesting pictures. Admittedly, in their mid-level smartphone, the Koreans were able to do more for macro photography than, for example, Realme in its latest flagship X3 SuperZoom.
In the absence of a telephoto lens, the zoom is implemented using the main camera, and this will naturally be a digital zoom. The maximum value is 10×. The zoom in this smartphone is better not to touch, it will not bring anything good.
There is a separate night mode, and it takes pictures on both regular and wide-angle lenses.
Telephone part and communications
The Exynos 9611 SoC modem theoretically supports 4G Cat. 12/13 networks with data download speeds of up to 600 Mbit/s and transmission speeds of up to 150 Mbit / s. The supported LTE frequencies include all the most popular ones in Russia: 4G FDD LTE B1(2100), B2 (1900), B3(1800), B4(AWS), B5(850), B7(2600), B8(900), B12(700), B13(700), B17(700), B20(800), B26(850), B28(700), B66(AWS-3). In practice, within the city limits of the Moscow region, the device demonstrates confident operation in wireless networks, does not lose connection, and quickly restores communication after a forced break.
Wi-Fi 802.11 a/b/g/n/ac and Bluetooth 5.0 wireless adapters are also available. Contactless payment via NFC is available.
The navigation module works with GPS (with A-GPS), with the domestic Glonass, with the Chinese Beidou, and with the European Galileo. The geomagnetic sensor is in place.
The voice of the interlocutor in the speaker is recognizable, the volume is rather insufficient for a noisy street. The vibration motor is well felt. There is only one radio modem in the smartphone.
Software and multimedia