Lab – The Xiaomi 13 Ultra: a really ultra-bright screen?

After generations of “Ultra” reserved for the Chinese market, Xiaomi is changing its tune. Its most ambitious flagship, a real technological showcase at a fairly prohibitive price, is therefore available in Europe. The Xiaomi 13 Ultra relies on an ultra-complete technical sheet – its full test is available to give you an idea – and on a few figures that caught our attention.

It is indeed the screen of the Xiaomi 13 Ultra that challenged us, although the smartphone is an accomplished photophone. It houses a rather classic panel for high-end: large diagonal of 6.73 inches, AMOLED technology, WQHD + definition 3200 x 1440 pixels, LTPO with refresh rate varying between 1 and 120 Hz … the essential is there. The calibration is successful, the brightness in standard mode is high, since it exceeds the 1300 cd / m² announced on the smartphone’s technical sheet: Xiaomi therefore delivers a resolutely high-end panel.

However, the manufacturer promises mountains and wonders. In addition to a standard brightness of 1300 cd / m², the smartphone is supposed to display up to 2600 nits when HDR content is submitted to it. For comparison, the Samsung Galaxy S23 Ultra does not announce more than 1750 cd / m² in peak HDR, the Honor Magic 5 Pro 1800 cd / m² at the maximum and the iPhone 14 Pro Max 2000 cd / m² at most. Will the most ambitious smartphone on the market to date be able to keep its promise?

As always, we placed the smartphone under our probes, subjecting it to our HDR test chart (100% white) and activating the automatic brightness. In our usual environment, with an ambient brightness of just under 300 lux, we did not exceed 1561 lux: a very good score, but still far from the promise displayed by Xiaomi.

More than 2000 cd/m², but not in all conditions

After investigation, it appeared to us that very specific conditions had to be met to access the full potential of the 13 Ultra. As the brand told us, the smartphone must be sufficiently charged (at least 18% battery), be subjected to a temperature of less than 35°C and, above all, the ambient light must reach at least 100,000lux. To get an idea of ​​what this represents, it more or less corresponds to the luminosity obtained in summer in full sun.

For our part, we simulated a luminosity exceeding 100,000 lux by placing our Xiaomi 13 Ultra as close as possible to a powerful halogen lamp (more than 150,000 lux), which allowed us to go a little further: we We then measured a maximum of 2262 cd/m². This value remained stable for a few tens of seconds, but began to drop after one minute.

In fact, it seems difficult for ordinary mortals to reach the figures announced by Xiaomi. First of all, the image must not be too dark (low gray level, close to white): in other words, it works easily with our 100% white target, but the level cannot necessarily be unlocked when watching a dark scene from a movie or series in HDR, for example. Added to this is the ambient light. Unless equipped with ultra-powerful lamps, the user will have to make do with daylight: in full summer sun, the thermometer climbs quickly, and the smartphone can exceed the 35°C recommended by the manufacturer – even in indoors, we were around 34°C during our tests. In short, we will be content to note that when the light is bright, the smartphone easily exceeds 1300 cd / m², and that HDR content benefits from a little over 1500 cd / m², even when the smartphone is used in current conditions: even without showing off, it’s already more than enough to make the most of it.