Represents the shortest pits and lands, and is the highest frequency part of the signal. I3 is always smaller than I11 because the smallest pits are at the limit of resolution of the optics. Low I3 can be caused by pits that are too small. Lower writing speed (higher capacity discs) will make the pits shorter, and I3 lower. Again, larger I3 is better, up to a point. Minimum allowed is 0.30, and maximum is 0.60.