A method is described of determining the distance (50, 56) of a projection point (24) of a first imaging beam (22) of imaging device (20) from a measuring point (28) of a measuring device (26) or from a second projection point (36) of a second imaging beam (34) of a second imaging device (32) on the surface (10) of a printing form (12), both the projection point (24) of the first imaging beam (22) and the measuring point (28) of the measuring device (26) or the second projection point (36) being movable in relation to the surface (10) of the printing form (12). In the method, the reflected light intensity of at least a part of a pattern (84), which is produced by the first imaging beam (22) on the printing form (12), is measured as a function of the position of a measuring device (26), so that the distance (50, 56) may be formed as the difference of the position of the measuring device (26) and the correlated position of the imaging beam (22), at which the imaging beam (22) was located when the part of the first pattern (84) was written. The method may advantageously be used in a method of correcting the time triggering of an imaging beam (22), using which a projection point (24) may be produced on a surface (10) of a printing form (12).