Slow motion video, when done right, can be awesome. The Asus Zenfone 7 Pro understands how great slow-motion videos can be.
Until the last decade, shooting slow motion videos required large, heavy, and expensive cameras. However, smartphones have had slow motion functions for a number of years. Heck, some newer Huawei devices can record video at 7680 fps – albeit with a heavy loss of quality. The limitation is that as the frame rate increases, the quality usually decreases. This loss of quality can take many forms – resolution, reduced field of view, image interpolation, and high compression.
A typical smartphone can record 720p slow motion at 120 fps. A flagship can potentially record 1080p at 240 fps and 720p at 960 fps. If you want to record Ultra HD 4K, you’ll usually stick to 60 frames per second, even on the highest-priced smartphones.
The Zenfone 7 Pro can record 4K video at up to 120 frames per second – and it’s fantastic.
Our verdict: Asus Zenfone 7 Pro review
How does it work?
Above you can see some slow motion videos captured with the Asus Zenfone 7 Pro. Let’s take a closer look at the clips in the order they appear in the video.
First, I shot a video practicing soccer freestyle. The lighting is quite challenging as it is shaded under tall walls and fences and harsh sunlight peeks through the trees. The footage looks sharp, with precise color and even exposure. There is a little noise on the right side of the photo where the light is falling off. However, in slow motion shots, this is impressively detailed and sharp.
Next, I kicked some sand on a beach to improve the Zenfone 7 Pro’s detail resolution ability. You can easily see individual grains of sand flying up from the beach. In this clip, the phone had to be exposed to the very harsh sunlight. As a result, my shorts and shoes are almost crushed. There are still details in the fabric of both, but not much.
This slow motion footage is impressively detailed and sharp.
A general shot of the beach will allow you to spot the seagulls and waves in the sand. Highlights haven’t disappeared in the sky either. You can still see the clouds and there is even some detail and color in the factory and the surrounding trees in the distance. This was the most difficult clip to capture because of the immense dynamic range. Nevertheless, the Zenfone made it. Very impressive!
Next, I put an SD card on my desk while holding the phone. This is dim light so you can see some noise and noise reduction artifacts on the desk pad and SD card itself. Since the shutter speed has to be reduced to take in more light, slow motion is not as sharp.
In the following clips with water flowing out of taps, the videos are sharp but the phone cannot capture the footage fast enough to make the water appear clear. 120 fps is not enough, but switching to faster frame rates will result in much worse looking footage. This lower resolution footage is more like what we’re used to from other smartphones and while adequate, it is nowhere near as impressive.
Would you like to see the slow motion clips yourself in full quality? You can find them in this Google Drive folder.
Zenfone 7 Pro: Taking Slo-Mo Video to the Next Level
It’s surprising to see such an advanced feature from a niche device for $ 799 when so many more expensive phones don’t have it. We noticed this loss of functionality when the phone started. After some use during the review period, we decided to take a deeper dive and push it to its limits.
The Ultra HD 4K 120fps slow motion is a continuous shooting mode, not a burst. This means you don’t have to come across the record at the right time. I recorded a 25 minute Ultra HD 4K 120fps video and while the phone was getting hot it did not get uncomfortably hot and did not shut down.
See also: The best Android camera phones you can get
Typically, you are more likely to shoot shorter slow motion videos as it will slow down the final product. I have photographed in a variety of conditions including daylight, low light, outdoors, indoors, with a handheld, and on a tripod.
The data rate is a crucial element for video quality. The higher the data rate, the larger the files and the clearer the picture. Since the Zenfone 7 Pro is equipped with 256 GB of memory, the former shouldn’t be a problem. The Zenfone 7 Pro consumes ~ 120 Mbit / s, which is very high for typical smartphone videos at around 50 to 80 Mbit / s. This high data rate video means the slow motion files are very clear and sharp considering they are from a smartphone.
You can slow down the 120 fps slow motion footage using the phone’s gallery app. This is convenient for posting the slowed down video on social media. By default, the footage is not verified. This means that when you upload it to a PC, you get the real-time clip in full resolution and full length with audio that you can slow down to match the frame rate of a project. However, it has to be mentioned that in this mode you can use the primary camera.
Asus’ quirky camera phone knows how great slow-motion videos can be.
Overall, the Zenfone 7 Pro records slow motion videos with 120 frames per second and Ultra HD 4K resolution in good quality. The footage is sharp and there is surprising dynamic range at this frame rate. The phone does a serious job of making the footage look usable. It’s one of the best 120 fps continuous slow motion footage we’ve seen from any smartphone – captured in 4K to boot.
With Samsung, Apple, Google, Huawei and many other smartphone brands setting slow motion to 1080p, Asus’ whimsical camera phone offers a little something extra for those who want to experiment with slow motion movies without buying a fancy DSLR.