Synthetic HDR images

Computer-created HDR images were first produced with various renderers, notably Radiance.[citation needed] This allowed for more realistic renditions of modelled scenes because the units used were based on actual physical units e.g. watts/steradian/m². It made it possible for the lighting of a real scene to be simulated and the output to be used to make lighting choices (assuming the geometry, lighting, and materials were an accurate representation of the real scene).
At the 1997 SIGGRAPH, Paul Debevec presented his paper entitled "Recovering High Dynamic Range Radiance Maps from Photographs".[10] It described photographing the same scene many times with a wide range of exposure settings and combining those separate exposures into one HDR image. This HDR image captured a higher dynamic range of the viewed scene, from the dark shadows all the way up to bright lights or reflected highlights.
A year later at SIGGRAPH '98, Debevec presented "Rendering Synthetic Objects into Real Scenes: Bridging Traditional and Image-Based Graphics with Global Illumination and High Dynamic Range Photography".[11] In this paper he used his previous technique to photograph a shiny chrome ball to produce what he called a "light probe", essentially an HDR environment map. This light probe could then be used in the rendering of a synthetic scene. Unlike a normal environment map that simply provides something to show in reflections or refractions, the light probe also provided the light for the scene. In fact, it was the only light source. This added an unprecedented level of realism, supplying real-world lighting data to the whole lighting model. Also presented at later SIGGRAPH, Bunkspeed showed Hypershot and later on Hypermove software to create 'photorealistic' images from 3 components: Background image - a high resolution photograph (eg 22MPixel digital image), environment file - a 360-degree view of all light sources including reflections (eg Spheron camera image or a completely synthetic environment[12] ) and a computer generated subject model. There are material libraries available with different reflective characteristics that can be used to dynamically modify the computer generated image.
HDRI lighting plays a great part in movie making when computer 3D objects are to be integrated into real-life scenes.
HDRI has made its move to consumer in-camera systems and is available on the Pentax K-7 Digital SLR by utilizing its HDR image capture mode.