Composition

One rule of portraiture is the rule of thirds. This suggests that, if you were to split the picture into thirds, both horizontally and vertically, the main point of interest should be located where these lines cross. Lewis has been programmed to arrange photos with faces at these strategic points.

In photography it is also important to avoid unnecessary empty space and maximize the amount of important information in the picture. This sometimes conflicts with the rule of thirds, since placing faces at these points may result in too sparse of an image. Lewis must balance these composition goals against one another to find the optimal photograph.

Lewis has also been given the freedom to be "daring" at times. By occasionally breaking the rules of photography and getting feedback about the results, Lewis can learn when and where it.s appropriate to deviate from convention. This allows the robot to refine its composition sense beyond simple pre-programmed rules.