Abstract: Methods and apparatus for recording varying electric signals with a plurality of electrically actuable light gates illuminate the light gates with light of a first intensity above zero light intensity and provide a light-sensitive recording medium sensitive to illumination levels at light intensities including the mentioned first light intensity and starting at a second light intensity below such first intensity and above zero light intensity. These methods and apparatus precondition the light gates to subsequent opening in response to varying electric signals by electrically biasing the light gates to an initially open condition wherein the gates pass light from the mentioned illumination at an intensity below the second light intensity. The recording medium is thus exposed to light passed by the preconditioned gates at below the second intensity.