We present a study into the small particle size and resolution limits of Light Induced Dielectrophoresis (LIDEP). Here the illumination of a photoconductive layer creates virtual electrodes whose associated electric field gradients cause the dielectrophoretic response of the particles. In this way a potential energy landscape can be created that is optically controlled giving reconfigurable control over a large area . In this paper we discuss the interlinked limits of size of particle it is possible to manipulate and the resolution these particles can be manipulated with. We compare traditional dielectrophoresis (DEP) experiments with LIDEP experiments, and discuss the mechanisms behind the physical limits comparing the effects of carrier diffusion verses the spreading of the electric fields in the medium.