I was very surprised at the image quality from a friend's Sony phone a couple of years back. A few of us were walking up Ben Nevis (the UK's tallest mountain). I couldn't do much in the way of photography since the only camera I had with me was my wife's DSLR (I took hers on the basis it was smaller and lighter than mine) with a lens with a 77mm front element and it was raining. He took a picture with his camera and it came out very much better than I expected. Maybe not up to the standard of something you'd sell but remarkably good given it was just a camera built into a phone.