What is the aperture of the iPhone 5s camera?

Apple has improved the specs on the iPhone 5s iSight camera. For those who are wondering, the new camera has improved low-light sensitivity thanks in part to a larger aperture.

The aperture on the iPhone 5s camera is f/2.2. This is compared to the aperture on the iPhone 5, iPhone 5c and iPhone 4s at f/2.4.