HDR stands for High Dynamic Range. It’s a photography technique using multiple pictures, each at different levels of exposure, to bring out detail that would not be visible with just one exposure. For the picture of the church to your left, I placed my camera on a tripod and took three RAW exposures, one at “correct” exposure (capturing all mid range detail, extreme highlights “blowing out” pure white, and the darkest shadows going completely black), one under exposed (shadow areas went black, only visible detail in extreme highlights), and one over exposed (highlight areas went white, only visible detail in darkest shadow areas). Then I merged them together using a program called Photomatix. It processes the images and pulls all the usable detail from all three RAW files, giving you much more dynamic range than can be displayed with just one exposure.
Once Photomatix has worked it’s magic, it goes through a process called tone mapping where you further adjust, through the use of various sliders, things like color saturation, effect smoothing, and micro-contrast. When this is done you save the file as a Jpeg or Tiff. You might think at this point that you are done. You would be wrong. You see, the capturing of all that information is what makes HDR photographs look so bold, but you cant use all of it because it would look otherworldly, false. No one could connect with your subject. You have to do some further editing to emphasize the parts of the picture you want to draw the viewer’s eye to, and de-emphasize what would cause confusion, or distract your viewer’s attention.
So It’s off to Photoshop for color, levels, and curves adjustment. Emphasize areas more or less with some burning and dodging. Maybe bring the original correct exposure in also as a layer and combine parts of that image using layer masks. When all of that is done, it’s time to think about noise. The HDR process introduces a lot of noise to the image, and you’ll want to manage that with a program like Imagenomic’s Noiseware or Noise Ninja.
HDR is a fun way to bring out more detail in your photos, just remember your tripod and your patience. The post processing is pretty involved, but here is a tutorial that will make it less confusing. Enjoy!