HDRI

"High Dynamic Range images have a much greater amount of illumination information than can be reproduced with a standard display device or captured using a conventional camera with a single exposure. From the brightest light source to the darkest shadow, their pixel values are directly proportional to the light energy in the scene. From a computer graphics perspective, this means that you can use the HDRI file for image-based lighting.
Image-based lighting works just like real world illumination. The environment provides not just reflections but the full intensity of any natural or artificial light source present. If you are looking for the ultimate in realism, there's no better way to light a 3D model. " to find out more...
For some tutorials using HDRI with 3dmax, click here.
Image from http://www.hdri-studio.com/products.html
Passage from http://www.hdri-studio.com/technical.html