In this paper we show how to improve greatly the resolution of IR thermography by using two different signal treatment methods: a static treatment and a dynamical treatment. This signal processing allows the study of 100 cm(2) cells under low-forward or reverse-polarization conditions. Static and dynamical methods have both good resolutions: static has the advantage of being fast, and dynamical method does not need any reference image nor cooling system. We have shown that IR thermography is an interesting method for investigating shunts in solar cells. Thermal maps and I-V characterization of the hot spots show that the origin and the behavior of the shunts are varied and their influence on the efficiency is probably more important than what is usually thought.