As a part of exercise in our class, we are to research and explore various possibilities of simulating natural light when combining rendered object with a photo background.
The simplest solution is to use two directional lights. One is to simulate sun, the other is to simulate reflected light. This work for quick sketches, but is obviously not suitable for serious visuals.
A little bit more advanced solution would be using light dome or built in Maya function to simulate daylight:
Using image based light:
In the next step we are going to try the more advanced solution, which is HDRi enviroball light.