Apple’s latest iPhone 15 Pro has ROM limitations in its ProRes video recording function. Specifically, the 128GB ROM version can only record 1080p ProRes videos at 30fps unless the user records the video directly to an external storage device. Models with 256GB or above can support 4K ProRes video recording at 60fps without an external storage device.
Although Apple does not mention this limitation directly on the iPhone 15 Pro technical specifications page on its official website, its existence can be seen when comparing it with other iPhone models in the Apple Store app. This restriction also applies to the 128GB versions of the iPhone 13 Pro and iPhone 14 Pro, but these devices cannot record ProRes video to external storage. However, this restriction does not apply to the iPhone 15 Pro Max, because the starting storage space of this model is 256GB.
The file size of ProRes video is very large. Apple says that one minute of 10-bit ProRes video is approximately 1.7GB at 1080p and approximately 6GB at 4K. Apple may believe that providing 4K ProRes video recording on a model with 128GB storage space may affect the user experience. However, with the option of recording to external storage, this problem is no longer an obstacle.
ProRes is a series of encoders launched by Apple that can compress videos into smaller file sizes while maintaining high quality. It should be noted that the standard version of iPhone 15 and iPhone 15 Plus still do not support the ProRes video recording function.
In short, Apple’s ProRes video recording feature on the iPhone 15 Pro is limited by storage space. Although the 128GB storage version can only record 1080p ProRes videos, users can solve this problem through external storage devices. Models with 256GB or above can directly support higher-quality 4K ProRes video recording. This restriction also applies to the 128GB versions of the iPhone 13 Pro and iPhone 14 Pro, but not the iPhone 15 Pro Max. The ProRes encoder compresses videos into smaller file sizes while maintaining high quality. It should be noted that the standard version of iPhone 15 and iPhone 15 Plus do not support the ProRes video recording function.
