Can I shoot RAW photos with my iPhone X?

RAW photos? Yes. I use an app called ProCam 5 and yes you can shoot RAW pictures. But I've never used my iPhone like that.

But I agree with everything everyone has said so far.

By the way, it's paid software (ProCam 5). I think it's free to try out, so you might want to experiment with it.

Allan Eckert wrote:

If you need larger resolution, get a real camera instead of the toy in the iPhone.

Any attempt to increase resolution will only lead to false increase in size without a true increase in resolution. If it is not there, there is no way to create it after the fact. It must be there from the beginning.

The native resolution is real, but it's a tiny sensor and thus will always be dealing with noise in low light conditions. A bigger sensor and a large lens will be needed for better images. Apple's cameras are good for what they are, but they don't do miracles.

No. Under iOS 11 the photos are natively encoded in HEIC.

https://en.wikipedia.org/wiki/High_Efficiency_Image_File_Format

If you need larger resolution, get a real camera instead of the toy in the iPhone.

Any attempt to increase resolution will only lead to false increase in size without a true increase in resolution. If it is not there, there is no way to create it after the fact. It must be there from the beginning.

Allan Eckert wrote:

Hence my suggestion to get a real camera if you need real resolution.

Well - it's more than just about "resolution". There's always been the megapixel war, because bigger numbers tend to sell. A friend of mine does freelance photography, and his old (circa 2002) Canon EOS 1D with a 4-megapixel full-frame (35 mm film sized) sensor and a professional f/2.8 prime lens will still put any camera phone to shame. I think the sensor is literally over 100 times larger than that of an iPhone X.

Hence my suggestion to get a real camera if you need real resolution.