Abstract: A method is presented for characterizing and error in Monte Carlo realistic image synthesis calculations. An error metric has been developed that can be used to control the variance in the final picture by choosing both the number of rays to be cast into the iamge plane and the number of rays to be spawned at each bounce in the environment. The method provides specific guidance in how to apply Russian Roulette and splitting at each level of the ray tree. An initial implementation of the method has been done to test the theory and to illustrate its mechanics.