I created all the renderings on Sweet Hall machines. Setting up wasnt too hard. And most of the files just required playing around with the position and number of lights. For most of the configurations, I first thought, that it is required to do some tone mapping in Photoshop to get the intensities exactly right. But later, found that I needed to do just some more tricks with the scene files.
For Configuration 1, I did a number of adjustments with the placing and intensity of the light, but could not really get a completely black background. A very small cone angle helped get the black background finally.
For configuration 2, The light needed to be kept close enough to give the desired effect, but that also produced a noisy image. After tweaking the radius and the intensities, I got an image that was quite close. Most of the positioning of the lights in all the configurations was guessed by having a look on the shadows casted on the actual images.
For Configuration 3, nothing special needed to be done. This was easy, except it took some time to figure out how the area light was positioned. By a closer look, it could be observed that the right ear was not really lit and the right cheek was. Thus, it was important to make the radius of the area light small enough to cover only the cheek.
For Configuration 4, I couldnt really get the first light well. The overall image with the four light looks quite close, however the soft shadows on the actual image gave an impression that area lights were used instead of source lights.