The iPhone camera is pretty awesome. It’s not a Nikon, Canon or whatever, by any means. Still, it’s one of the most widely-used cameras out there according to Flickr data (actually, it is the most widely-used camera out there, according to Flickr.)
This photo (rather set of several photos) comes from Reddit. Someone took a picture with each iPhone, and then took a closer up, detailed zoom of the photo to show the quality between models. It’s really interesting. You can take a look at the full picture below. It’s every iPhone up to the 5.