Need to get size of the photo that will be done before it's done. EXPO

I`m using expo-camera for doing selfie. When i do photo - i got an object with photo width, height and photo uri. Width and height always the same and specific to device.

But for some reasons ( need to show user warnings) i need to know size of the photo that will be done on my selfie camera before i do this photo. I think i can take this data somewhere (specific to device), but can not find it.

I tried to find info in Camera.Constants but did not find anything there. Also checked Expo Constants. No information too.

Anyone can help me?