Lab – What are the selfie modules under the screen worth?

In the world of smartphones, the screen free of any photographic artifact has long been considered the new quest for the Holy Grail. Thanks to advances in technology, manufacturers are now able to offer mobiles with panels without notches or punches. The trick: place a sensor under the screen and play with the pixel density of the latter.

This process, far from always being invisible to the naked eye, has already been adopted by two smartphones, the Axon 30 5G from ZTE, unavailable in France, and the Samsung Galaxy Z Fold 3, a model equipped with a screen folding and marketed on our territory.

A very discreet solution at ZTE

At ZTE, the 16-megapixel front sensor with an f/2.5 aperture is hidden at the top of the 6.9-inch AMOLED screen. In hand, the result is stunning: we absolutely do not see the module dedicated to selfies.

You have to stand at an angle and under a certain light to distinguish a small rectangular shape under the slab, but it remains really very tenuous, whether the wallpaper is light or dark. Placed under an electron microscope, it is possible to observe more precisely how the light filters through the screen.

We then see a clear distinction in the arrangement of the pixels on the screen. At the bottom, the pixels, square or rectangular, are closer together. At the top, where the photo module is nestled, the pixels turn out to be smaller and rounder; they are then further apart. This loss of density allows light to reach the sensor.

A less subtle option at Samsung

With its Galaxy Z Fold 3 foldable smartphone, Samsung is adopting a solution similar to that of ZTE, but much less discreet. Thus, the module of only 4 megapixels with its optics opening at f / 1.8 is integrated at the top of the right inner pane of the screen.

If it is not as visible as a classic punch, it is noticed almost immediately, especially when the wallpaper is light in color. It takes the shape of a small octagon and the pixels appear even to the naked eye. A passage under the microscope and we better understand the original layout of the pixels.

At the bottom of the image, you observe the “classic” screen, where the pixels are round, and above, the notch housing the selfie module has a distinctly different structure. Eight-pixel islands have been arranged so that light can flow between them. This atypical construction does not effectively hide the module from the rest of the screen. But does it have an impact on the final quality of the image? This is what we are going to see now.

The Z Fold 3 sensor lacks definition

Unsurprisingly, the selfie modules of the two smartphones do not shine with their quality. This sensor is often the poor relation of mobile photography. There is little doubt that the constraints associated with capturing shots through a slab, even if it is more transparent than usual, do not help.

By day

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The ZTE Axon 30 5G and its 16-megapixel sensor does much better than the Z Fold 3 with only a 4-megapixel sensor. Admittedly, the snapshot of the Chinese smartphone suffers from an unattractive white veil, but it is more detailed; it is possible to read the inscriptions, in particular on the cover of the book, where at Samsung we cannot even decipher them.

By night

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In low light, the two smartphones are really struggling. Again, the ZTE does a little better, but nothing exceptional. For its part, between the low definition of the sensor and the excessive smoothing, the Z Fold 3 is really not at the party. We jump back a few years. Note: we will make sure to make our video calls with adequate lighting.

Our pick for selfies: the ZTE Axon 30 5G

The ZTE Axon 30 5G is the big winner of this comparison. Its most discreet module provides superior image quality to that offered by the Samsung Galaxy Z Fold 3, handicapped by a low definition sensor.