What is High Dynamic Range?
High Dynamic Range (HDR) is a set of techniques that allow a greater dynamic range of luminances between the lightest and darkest areas of an image than standard digital imaging techniques or photographic methods. By using these different techniques, you can create an image that shows more detail in shadows and highlights than you can with a regular photo from standard cameras.
Using HDR techniques requires additional software like Photomatix and Adobe Photoshop. The photographer has all control on how he or she wants the end photograph to look. Many photographers use this special technique to give their photos an "unrealistic" look. They can create very natural looking photos or can use many different settings and create vibrant, atmospheric and emotive photos.