Dual photo delivery is supposed to simultaneously capture a photo with the wide and tele cameras, but the tele photo looks like a digitally zoomed version of the wide, not optically zoomed:
By contrast, here's a 2x photo shot with the iPhone camera app:
Notice how much clearer it is, as you'd expect from the tele camera?
In case this was an issue with this specific scene, I tried with another, with the same result.
In a third case, I found the tele photo returned by dual photo delivery
to have the same field of view as wide:
In both cases, the EXIF says that it's indeed from the tele camera (F2.4 aperture, 52mm focal length). If it is, why does the content look like a cropped and upscaled version from the wide camera?
This is on iPhone XS running iOS 12.1.3.
I tried doing the following:
- Clean in Xcode
- Clean build folder
- Delete DerivedData
- Uninstalled and reinstalled the app on the iPhone
But none of them helped.