Cameras in devices by Apple have always been top-notch. They don't challenge camera-phones such as the Lumia 1020, Xperia Z1 etc, but they always get the job done. The new A7 chipset brings with it a newer image signal processor, not to mention better optics and sensors. Have a look at some samples.
iPad Air,Mini Retina And iPhone 5s Camera Samples Compared
U can see clearly here that the iPhone 5s has a better and brighter lens. Even though the iPad Air and the iPhone 5s share the same A7 chipset, their image quality looks a lot different. A lot of noise is apparent in the iPad Air sample. The older iPad mini and the newer mini retina have almost the same image. No clear difference is apparent in-between them. Both have a noisy image although the older iPad mini produces somewhat better colours.
These are macro samples, again it is evident from the picture that the iPhone 5s captures the most detail with the most accurate colors. All other three images do not come close to the 5s. Even here noise is apparent in the image by iPad Air and mini retina. The older iPad mini does not cope well with macro.
Here are 'HDR' photos from the i devices. High dynamic range, which increases the dynamic range of an image by composing many pictures of different exposures into one, provides better image detail and stronger colors. The iPhone 5s shines here with the most crisp image and better differentiation of light and dark regions of the image. The iPad Air and the mini retina produce somewhat acceptable results while the older mini lags in this fight.
The Apple iPhone 5s has superior low light performance. Better when comparing its counterparts, better than many Android phones also. Expect the movie recording to be somewhat same on all four devices, with the exception of low light where the iPhone 5s with its better lens and sensor tramples the opposing iPads.