By filming in HDR, smartphones seek to capture more natural lights, in order to restore, for example, the rays of a sunny day with greater liveliness, and thus contrast with the softened rendering to which we are accustomed. A promise that will intrigue anyone who collects a lot of memories in video format.
To achieve this, smartphones rely on several new qualities. Their camera trick to capture wider ranges of light, from the cat lurking in the shadows to the reflections of the sun in the water. Their electronic chips record finer shades of brightness, and their memory stores, in addition to video, detailed information on the light intensity of the scene they are filming.
HDR video capture appeared in 2018, but “it initially turned out to be disappointing”, says Hervé Macudzinski, scientific director of imaging at DXOMark, a French test laboratory. To the point of first remaining hidden in the smartphone options. It’s only been eighteen months that some brands activate it automatically, a sign that they are beginning to be satisfied. We tested this function on the Xiaomi 12, the Samsung Galaxy S22 and the iPhone 13, three smartphones from the most popular brands costing around 800 euros – the medium ranges not yet having access to it. Does this function keep its promises to the point of making it a purchase criterion?
Xiaomi and Samsung struggling
Most of the test videos were shot outdoors and in daylight, conditions favorable to HDR. However, the images from the Xiaomi 12 turned out to be disappointing, rarely more vivid than the shots shot in the classic format. Color rendition deteriorated to the point that HDR images looked less natural. It seems that Xiaomi is aware of this since this function is, for the moment, optional.
At Samsung too, HDR is disabled on the Galaxy S22. The effects of HDR are just as discreet as on the Xiaomi. Some videos look a little more vivid in HDR, others duller, for an overall mixed result. At Samsung, colorimetry problems are acceptable as long as you don’t try to watch these videos on a screen other than that of a smartphone, and you make the mistake of broadcasting them on a low-end television: “The quality of HDR is then lower than that of shots filmed in the classic format”, found Mr. Macudzinski, who advises against activating this function on the S22. On a high-end screen, Samsung’s HDR videos do not suffer from this defect, but very often they look much less natural than those of the iPhone.
Astonishingly realistic apple
Only the images of the iPhone 13 seemed particularly vivid and natural to us in HDR, whether on the smartphone screen or on the two OLED televisions that were used for our tests, the Panasonic JZ2000E at the record light peak and the LG C2, often recommended by specialist media.
We noticed a clear improvement on two-thirds of the videos shot outdoors: the clouds seemed cut out by the light, the water seemed more vivid, the sun spots in the forest stood out in a natural way. Overall, the impression of relief and contrast was superior. Finally, these images gave off a feeling of frankly improved realism, to the point, sometimes, of giving the impression that we were crossing the screen. On these videos shot outdoors, failures were quite rare, even when it was raining.
Be careful, however: this improvement faded when viewing these videos on a screen exposed to direct sunlight. HDR only shines in dimly lit rooms. And videos shot indoors rarely looked better in this format. Many even looked slightly darker compared to the classic format. To the point that we would rather advise those who mainly shoot videos in dark environments to disable HDR. That said, as this technology is still in its infancy, we can hope that this problem will eventually be corrected.
The wall of sharing with loved ones
When you want to show your loved ones the beautiful HDR videos you have shot, it’s an obstacle course. Social networks are not very welcoming with HDR: many are not compatible, and when they are, most broadcast the video in a compressed format which attenuates the luminous impact. Display problems may occur: the image may appear too dark or too bright.
Sending the video directly to loved ones is a good solution if they have a high-end smartphone of the same brand and generation: we recommend using nearby wireless file sharing. But if they have a device that’s significantly older, or less high-end, their screen will rarely be bright enough for the visual impact to be appreciable. In addition, if the device is not of the same brand, it will not necessarily be able to play the video in optimal quality, because the brands of devices are engaged in a war of formats. Many TVs, computers, and smartphones only play HDR 10+ or its competitor Dolby Vision correctly, but not both. Apple devices, for example, are incompatible with videos from Samsung smartphones.
In short, it is often better to show your HDR videos on the smartphone that filmed them. If you want to play them on an HDR television, you will have to meet a daunting list of conditions. Thus, it must be able to display a high light peak and be compatible with the HDR format of the smartphone, and it will be necessary to avoid using a Chromecast to play video, Apple TV or any other wireless streaming system: this generally harms to image quality. The safest way is still to place the video on a USB key plugged into the TV.
Worse: iPhone videos are very difficult to extract from smartphone in HDR quality. Apple does everything to convert the video to a non-HDR format, to avoid display problems. To overcome this problem, the video must pass through the Files application. Exhausting!
For now, only Apple has mastered HDR video capture on smartphones. When filming in direct sunlight with the iPhone 13, the result is truly exciting. Back home, the video sometimes seems so realistic that it gives the impression of revisiting the place where we filmed, much more than a classic video.
But when filming indoors, the HDR shot is rather slightly less pleasant to watch. And since there is almost no safe and easy way to share HDR video with loved ones, this technology, as promising as it is, does not seem ready to become a purchase criterion for the general public yet.
Our test protocol: an obstacle course
For this comparison, we filmed about thirty double shots: first in HDR (high dynamic range), then immediately afterwards in classic format SDR (standard dynamic range). By chaining the reading of the two shots on a smartphone, the difference was immediately obvious: the HDR radiated. An illusion, we finally understood. Smartphones often increase the brightness of its screen during HDR playback, distorting the comparison. This is also one of the reasons why we cannot illustrate this article with HDR and SDR videos: their comparison would be misleading.
To eliminate this bias, we used a second smartphone of the same brand, of the same size, with an equivalent peak light: we broadcast the SDR video on its screen by increasing its brightness to reach the approximate level of HDR videos. After this manipulation, HDR scenes appeared much less flattering – except on iPhone.
A second test confused us: on the LG C2 television, we tried to erase the difference in brightness between SDR and HDR by activating the “maximum brightness” setting. The gap between the SDR and HDR images of the iPhone 13 then seemed much less obvious to us. Incidentally, we noted that this automation was aggressive, producing a less natural image in SDR. These observations came as no surprise to Hervé Macudzinski, Scientific Director of Imaging at DXOMark, a French testing lab:
“Videos from the iPhone 13 are filmed by an HDR sensor, whether they are then recorded in HDR or SDR. In these two formats, the difference in brightness between the whites and the blacks is therefore strictly identical. It is the number of shades of brightness, between white and black, that the HDR format improves. Let us add that the recording in the HDR format used by the iPhone, Dolby Vision, added to the video new information: indications on the light intensity inside the filmed scene. iPhone 13 SDR videos do not incorporate this information and their lights are less nuanced, but they remain excellent – it doesn’t surprise me that a television with very advanced automation can give them a boost by putting its above-average brightness to good use. However, I expect the result to be less clean and less natural than with an HDR video. »