iPhone 5 Camera Tests and iPhone 4S Comparison
As usual with new iPhone releases, Apple has created a webpage showing "actual photos taken with the iPhone 5". It is available here, and it features a gallery of six photos with an option to view them in full-size (the iPhone 5's camera shoots photos at at 3264×2248 pixels).
Curiously enough, Dpreview's Scott Everett recently took a photo of Big Sur in California (the location pictured above) with an angle very similar to Apple's one for the iPhone 5 (also embedded above). Because of this, Dpreview was able to closely compare the picture quality of the devices with the same subject. While the camera may appear to be the same, there are some notable differences.
Looking at the EXIF data of the images confirms Apple's assertion that this is a new sensor, despite the pixel count remaining the same. Close examination shows the iPhone 5 is using a 4.1mm lens to give a 33mm equivalent field of view, rather than the 4S's 4.3mm lens, which gave a 35mm equivalent view. This means the new sensor is a tiny fraction larger. The iPhone 5 has also selected ISO 50, 1/3EV below the 4S's minimum sensitivity of ISO 64.