A method and a device adapt the number of stepping motor cycles K to a temperature-dependent length change of a feed spindle in an exposer for recording printing originals. The length change is measured via a reference rod, which is disposed parallel to the feed direction of the exposure head carrier. A reference distance is disposed on the reference rod. The exposure head carrier is located on a feed spindle, which is driven by a stepping motor. A number K.sub.0 of cycles of the stepping motor per revolution of the exposure drum for a specific printing result is determined once. A corrected number K.sub.k of stepping motor cycles for achieving the same printed result is then determined as a function of the different temperature-dependent length changes of feed spindle and reference rod.