On iPhone 12 Pro and later Pro models with iOS 14.3 or later, you can take photos in Apple ProRAW. ProRAW gives you greater creative control when editing photos.
Not a chance. There's no technical reason the base iPhones won't be able to do it but it's always going to be a Pro/Pro Max exclusive feature. I could be wrong, we'll have to wait and see. Otherwise this would mean there's no way to capture 48MP native images on the base iPhone 15 (maybe a third party app will have the capability).
On iPhone 12 Pro and later Pro models with iOS 14.3 or later, you can take photos in Apple ProRAW. ProRAW gives you greater creative control when editing photos.
You can simply install an app like pro camera and shot raw images with every iPhone you choose. I even shot raw with my iPhone XR. Many 3rd Party camera apps are much more versatile in any case.