Basically there are two reasons to make an HDR (High Dynamic Range) photograph: necessity and creativity—and because those reasons often overlap, you’ll get great photos and be able to add your own personal touches along the way.
The « necessary » reason for making an HDR image is due to the fact that our eyes can perceive an extraordinary range of contrast in a scene, a range far greater than any camera’s sensor can capture. We see into a scene’s brightly lit areas, and we can also tell what’s going on in the shadows. The camera is going to have trouble capturing the ends of that drastic range. If you choose to meter for the highlights (the bright areas), you’ll lose pretty much all the detail in the shadow areas of the scene. Try it the other way—meter for the shadows—and it’s likely you’ll end up with what are commonly called « blown out » highlights.
A familiar example of that: a well-exposed room interior in which the windows are blazing with light. If you expose to capture what’s outside those windows, the room’s details are going to be lost in shadow. And when you shoot outdoors, the sunlight that creates bright highlights will also create dark shadows; expose for one and you lose detail in the other.
But when you make an HDR image, what you see is what you’re going to get because an HDR photograph results when you take a series of exposures—commonly called a bracket—to capture both highlights and shadow detail.
High Dynamic Range Photography
more by Tony Sweet
at Nikon Learn & Explore