The most surprising nugget Apple's including in iOS 4.1 is the ability to take HDR photos. You've seen plenty of these before—photographs with vibrant, unreal colors—but what are they exactly?
You know, photographs. The HDR stands for "high dynamic range"—the range between the lightest and darkest areas of the image—and the idea is that they look more similar to what your eyeball sees than regular photographs.
...made of several photos...
HDR images are achieved by blending several photos with different exposures—usually at least over-exposed and one under-exposed—to make for a more dynamic scene. Jobs suggested that the iPhone and iPod Touch would be shooting real HDR photos, that is, a combination of a few shots snapped in rapid succession, as opposed to just some software approximation of HDR.
...that look kinda unreal but pretty awesome.
HDR photos have long been maligned as a gimmick, creating over-saturated circus shots. But on a smartphone they kinda make sense—tons of people use apps like Hipstamatic and Camera+ to jazz up their photos, and built-in HDR is bound to give iPhone shots a bit of extra punch.