Aimed at professionals, the ProRes codec offers higher color fidelity and less compression, and it is often used for commercials, feature films, and TV broadcasts, which is testament to the high quality results that it can achieve.
A one-minute 10-bit HDR ProRes video takes up 1.7GB in HD mode. For that reason, recording ProRes video at 4K at 30 frames per second requires 256, 512, or 1TB of iPhone storage capacity.
In other words, if you have an iPhone 13 Pro or iPhone 13 Pro Max with the base 128GB of storage, you'll be limited to shooting 1080p ProRes video at 30 frames per second.