The iPhone 13 Pro can shoot videos in ProRes since the update to iOS 15.1. We took the opportunity to dissect this format with image professionals.
The iOS 15.1 update, released at the end of October 2021, enabled two features promised by Apple: SharePlay and ProRes mode in the camera. The latter will not speak to many people, since it is a fairly specific technicality in the world of professional video. For Apple, this is to offer recording in 4K at 30 frames per second for iPhone 13 Pro models equipped with 256 GB of storage and up to 1080p at 30 frames per second for models with 128 GB. storage — the limit is easily understood when you see the size of the files.
But is this addition of real interest to the user of an iPhone? That's the question everyone asks and we asked video and color grading professionals.
iPhone 13 Pro
Source: Louise Audry for Numerama
ProRes on iPhone 13 Pro: what is it?
The iPhone 13 Pro is Apple's latest high-end smartphone. The ProRes codec is a way of encoding video in digital format, which promises minimal loss in the information the camera captures. It's hard to stay clear without going into overly advanced technical details: remember that a video file, even in 4K at 60 frames per second, is extremely compressed to have a decent size, which is good for general public use, but not suitable for image professionals who turn to "lossless" codecs capable of retaining the maximum amount of information.
Reserved for film sets, TV series or advertising, "lossless" (RAW) codecs have the particularity of creating extremely large files (count several GB per minute), but which offer great latitude in editing. Typically, a color grading professional will know how to turn day into night on a video, or change the color of a building. The more information there is (color, luminosity, etc.), the more the files are modifiable. Apple is positioned in this sector and, like others, offers its own codecs to professionals who traditionally use them on cameras. The ProRes format is not considered "lossless" (a ProRes Raw version exists elsewhere), but is a sufficiently uncompressed encoding to be used in a professional setting.
Porting the ProRes codec to iPhone 13 Pro is therefore a message sent to image professionals: filming on the iPhone theoretically allows you to create the same files as those you use daily with dedicated equipment.
The green building is red in real life. The colorimetry information is so extensive that it can be modified without "glitch"
Source: Anthony Wonner for Numerama
Are iPhone 13 Pro ProRes movies real ProRes files?
Not familiar with video techniques to tell the difference between a classic video file and a ProRes file, I asked Anthony Wonner, videographer for Frandroid, to do some tests on the files recorded by an iPhone 13 Pro. First observation: Apple did not lie about the goods. The file is encoded in ProRes 422, in every respect similar to that which can be found on professional cameras. The iPhone 13 Pro, at least on this part, therefore plays on equal terms with the most advanced capture tools.
The information contained in the file is also much more numerous than in a classic 4K file, taken with the same iPhone. When you change the color of a building in post-production, you see artifacts appear on the classic 4K video, which disappear on the ProRes version. This behavior is expected of such a file — and the size of the videos attests to the presence of additional information. The delta is also mind-blowing: as you can see in the screenshot below, the 11-second ProRes file weighs 1.06 GB, compared to 33.5 MB for the same file of the same sequence in AAC classic.
And yes, both are in 4K.
The same 11 second video in both formats
Source: Numerama screenshot
How to Enable ProRes Mode on iPhone 13 Pro
ProRes format is enabled
Source: Numerama screenshot
Are ProRes files taken by the Camera app usable by professionals?
If we do have a ProRes file of the quality we would expect, it is however not possible, to date, to say that it is a video file that a film crew would use. In question, mainly, the Camera application of the iPhone, which does not have a manual mode. Studied by calibrators and video professionals whom we contacted, the ProRes files taken by the iPhone immediately revealed their weaknesses: "The codec is well mastered, we have a lot of information, but we feel that it is a smartphone image”, summarizes Anthony Wonner. Therefore, directors who use an iPhone on a set will have to do so knowingly: they will seek to have a smartphone effect on the shot, and not to reproduce the quality of a camera and a lens exactly. . For those, the ProRes mode could clearly be useful.
On the other hand, the Camera application has a flaw that can exasperate: without manual or professional mode, “it constantly adjusts exposure, white balance and tint”. This is an advantage for the general public, since the work is generally well done: we end up with films that are correctly exposed and satisfactory to the eye. But in the context of a professional set and the shooting of a film, it becomes "hell to calibrate", because everything has to be re-corrected behind. To sum up, Apple's software is suitable for general public use and adds a ProRes option dedicated to professionals without adjusting its operation. To give a metaphor, it would be like putting a Formula 1 engine in a Tesla on Autopilot.
That said, it should be noted that a solution exists: do not use the Camera application. The reference, used by image professionals, is called FiLMiC Pro. Much more powerful and customizable than the Apple application, it also allows you to film in ProRes format on iPhone 13 and iPhone 13 Pro. On this rather expensive application if we add options to it (but painless in the budget of any film), it is possible to film in manual mode and to adjust camera parameters that Apple does not allow to be adjusted in its native app. Therefore, to have ProRes files that are not affected by Apple's algorithms dedicated to the general public, FiLMiC becomes the only valid option.
ProRes mode recalls the limits of the Lightning port
There remains a concern that no application will be able to resolve to date. The iPhone 13 Pro have only one connector: a Lightning port. If we omit the need to have an additional cable permanently to charge an iPhone, when all the rest of the Apple range has gone to USB-C, we must recognize that the Lightning port does not bother us more than that for general public use. On the other hand, when Apple provides tools like ProRes mode to professionals, it becomes a real problem.
During a shoot, managing the storage of video files is essential. Devices nowadays store files directly on SD card or SSD drives. This allows the operators of these machines to change a disc or a card on the fly if they are full. The time of the operation is counted in seconds and the filming can then resume. With an iPhone, none of this is possible: you have to connect the device to a computer, start a transfer, wait for the transfer to be completed, delete the files.
According to the latest news, the iPhone's Lightning connector is based on USB-2, which means that its transfer speed does not exceed the theoretical 60 MB/s (lower in practice). For comparison, USB-C 3.1 Gen2 can go up to 1.25 GB/s and USB-C Thunderbolt 3 in 2021 MacBook Pros or iPad Pros can go up to 5 GB/s. On the AirDrop side, the iPhone wireless transfer, it took us 29 seconds to transfer our 1GB file in an ideal environment, without any disturbance, from an iPhone 13 Pro to a MacBook Pro M1. Finally, there is the option to create an iCloud link, which allows you to send large files, but it depends on another parameter: having a good Internet connection and a good Wi-Fi network. On a movie set, and again more in a decor, it's far from common.
There remains an overkill solution that comes to mind so as not to have to worry about too long pause times on a set: buy several iPhone 13 Pro. Thus, when the first is in charge or in the process of being transferred, the second can take over on the shooting side. At €1,279 minimum for a 256 GB model capable of shooting in 4K, the bill goes up (but is to be put into perspective in relation to film cameras).
The ProRes mode of the iPhone 13 Pro: the strengths and the weaknesses
Clearly, the ProRes mode is a first step towards providing video tools that really speak to image professionals, on an iPhone 13 Pro which is already, according to numerous tests, the best smartphone on the market. to make video. But if the codec is respected, Apple still has a long way to go for it to be really usable in all shooting conditions.
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