High-Dynamic-Range Photography is a new Technic in photography to capture hidden details of a subject due to over or too less luminosity. In a normal photograph when over luminous area like sky is total burned out and on the other hand the region with shadow or less lights lacks in details for that region, HDR photography is the best solution to bring out details of those region in the photo. To capture these details at first place there are multiple shots are taken with purposely under or over exposures which is the only way to get the details of those areas. the number of shots required depend on diversity of luminosity of the frame. usually 3 Photos do a gr8 job but for professional jobs 5 – 9 shots are also taken with different exposures.
These different exposure shots are then merged together in special HDR softwares to bring out details from other exposures. the final image generated by this process has lot of data in it than any normal photo which then can be toned mapped as per users preference. usually these HDR images looks very colorful and dramatic is because it has lot of preserved data in it. the Lost color data of sky is retrieved from under exposed shot details in dark areas or shadows are retrieved from a over exposed shot which even human eyes can’t see in one go, Thatz the reason it looks amended sometimes.