A copier is designed to copy negatives of different sizes onto copying material of different widths. The negatives and copying material are supplied from rolls. The copier includes the following manually controlled components: (i) a set of interchangeable film guides which are used at a scanning station and are slotted to permit photoelectric scanning of the negatives; (ii) a set of interchangeable masks for masking the negatives during copying; (iii) a set of light shafts for illuminating the negatives during copying; and (iv) a movable guide unit for the copying material. A computer associated with the copier is arranged to receive signals indicative of the following manually obtained settings: (a) the type of dimensions of the particular film guide installed in the copier; (b) the type of dimensions of the particular film mask installed in the copier; (c) the type of light shaft installed in the copier or the cross-sectional area of the outlet aperture for the light beam; and (d) the position of the guide unit for the copying material which is related to the width of the latter. The copier further includes a motorized mask for regulating the length of copying material to be exposed, and an adjustable objective having motorized lens elements. The motors for the motorized mask and the lens elements are controlled by the computer. The computer has a memory which stores all possible combinations of settings for the manually controlled and motorized components. When the size of a negative to be copied changes, these components are adjusted for the new size. The manually controlled components are adjusted first. Prior to adjustment of the motorized components, the computer checks the settings of the manually controlled components against the stored combinations of settings to ascertain whether the particular combination of manual settings is possible.