1. A method for generating a dynamically corrected look-up table for modulating the intensity of actinic radiation incident on an imaging element comprising the steps of: (a) modulating the intensity of actinic radiation representative of an image having a predetermined number of variable optical density levels in accordance with a dynamically corrected look-up table; (b) exposing an imaging element to the modulated actinic radiation representative of the image; (c) modulating the intensity of the actinic radiation with information representative of a step wedge having a predetermined number of known optical density levels using the dynamically corrected look-up table; (d) exposing the imaging element to the actinic radiation modulated by the step wedge information; (e) developing the image and step wedge on the imaging element; (f) comparing the optical density levels of the developed step wedge to the known optical density levels; (g) generating a correction signal based on the difference between the developed step wedge optical density and the known optical density levels, and (h) correcting the look-up table in accordance with the correction signal.