Definition: High Dynamic Range, or HDR, is a digital photography technique whereby multiple exposures of the same scene are layered and merged using image editing software to create a more realistic image, or a dramatic effect. The combined exposures can display a wider range of tonal values than what the digital camera is capable of recording in a single image.
Adobe Photoshop and many other photo editors and digital darkroom applications offer tools and features to create high dynamic range effects. Photographers who wish to experiment with HDR imaging in photo editing software must capture a series of standard photos shot at different exposures, generally with a tripod and exposure bracketing.
Adobe Photoshop first introduced HDR tools in 2005 with the "Merge to HDR" feature in Photoshop CS2. In 2010 with the release of Photoshop CS5, this feature was expanded to HDR Pro, adding more options and controls. Photoshop CS5 also introduced an HDR Toning feature, which allows users to simulate HDR effects using a single image rather than requiring multiple exposures to be captured in advance.
Also Known As: tone mapping, hdri, high dynamic range imaging