High Dynamic Range (HDR) photography is a system for recording more detail in shadows and highlights than standard 24-bit photography is designed to handle. The greater the range between the brightest and darkest points in a photo, the more it can benefit from HDR.
The iPad mini 4 is faster, thinner, taller, and lighter than the iPad mini 3, boasting a 30% faster CPU and 60% faster graphics, which it replaces. That’s due in part to the 1.5 GHz A8 processor and in part to having 2 MB of system memory.
The big difference between the iPad mini 2 and iPad mini 3 is the addition of Apple’s fingerprint sensor in the Home button of the Mini 3. The small difference is the addition of gold to space gray and silver finishes.
At first glance, you’d think this was the original iPad mini, but the 2G iPad mini (unofficially iPad mini 2) runs Apple’s A7 processor and has a Retina Display. The 64-bit A7 takes performance far beyond that of the earlier A5-based iPad mini.
A lot smaller and just half the weight of a full-sized iPad, the iPad mini squeezed the features of the iPad 2 into much more portable package with a 7.9″ screen.