1. A method for calibrating laser energy from a laser eye surgery system, the method comprising: transmitting a laser beam suitable for ablation of corneal tissue from a surface; scanning the laser beam across a calibration fixture having a feature; separating a sample laser energy from the beam at the surface during the scanning; measuring the sample laser energy during the scanning; measuring the laser energy transmitted past the feature during the scanning; and determining a calibration of the laser system by comparing the energy measurements.