Although you can use any image to light a scene this way, you will get the best results using a High Dynamic Range (HDR) image. That's because HDR images contain a greater range of illumination than regular images, making them better able to simulate real-world lighting.
For more information about using HDR Images in Softimage, see Using High Dynamic Range (HDR) Images.
Except where otherwise noted, this work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License