API photography is a method that saves more information from the motive during exposure, compared to normal photography. Separated visual information bits are saved in a rapid tempo. The speed of separation makes it possible to use the technique in fashion/people photography.
For ages photographers have had to accept the flattening of the 3D-world into a 2D-image. In the digital work following exposure it would be rewarding to have more than a flat image to work with: To be able to instantly have access to information about the effect that one separate light source has had on the image. Without interference from other light sources. Now this is possible.