This photograph of Memorial Stadium is both a high dynamic range (HDR) and a mini-planet. Located on the campus of the University of Illinois at Urbana-Champaign (UIUC), Memorial Stadium is the home of the university's football team. Go Fighting Illini!
The final mini-planet image is 52 megapixels, so it looks good even at poster sizes (just over 200 DPI if the long side is printed at 36 inches). Though, the dimensions are not quite standard poster size.
In high dynamic range photography, the scene being photographed is captured at multiple levels of light (exposures). This allows all portions of the scene, whether they are bright or dark, to be captured with sufficient detail in at least one of the different exposures. The brightest exposures provide detail in the darker areas of the scene, but wash out the brighter areas. Meanwhile, the darkest exposures provide detail in the brightest areas of the scene, but the darker areas are quite dim and hard to see.
Later during post-processing, the different exposures are combined using software to create a single high dynamic range image. The resulting HDR image includes all the details from across the scene, regardless of bright or dark areas particular portions of the scene were.
It is also common to remap the HDR image back into a standard dynamic range (SDR) image using a method known as tone mapping. Depending on the tone mapping method used, the resulting SDR image may look either realistic or unrealistic. Tone mapping is often necessary to share photos taken using HDR techniques since many of the most common image formats only support SDR.
More high dynamic range photographs I have taken can be found here.
Mini-planets are a fun and interesting variation of more traditional panoramas. Rather than combining the images in a grid-like layout, the images are stitched to form a circle. If you have a full 360 degree by 180 degree image of a scene, it is easy enough to create a mini-planet using software that simply remaps the image around a circle.
However, to create a mini-planet that is creative, fun, and looks good can be quite challenging. Like most photography, it requires being able to envision what the final result is going to look like before the first shot is ever taken. This includes understanding and imagining what will happen to the image as it passes through each step of processing. For mini-planets in particular, the scene being captured by the camera is going to be distorted quite a bit.
Here are some more mini-planet photographs that I have taken.