HDR photos consist of 3 to 9 photos of the same image taken in what is referred to as a Bracket. A Bracket is taking each photo with an exposure adjustment of 1 to 2 stops between each shot. In the case below there are 2 stops between each photo. It consists of 2 images under exposed, 1 normal exposure and 2 over exposed. The 5 shots are then blended together to produce a final image that contains all of the highlights found in the underexposures and all of the shadow detail found in the overexposed images. This produces an image that is rich with detail that cannot be obtained with just a single shot.