Abstract: During the processing of an order in a photographic printer, a developed copy film strip can be scanned negative by negative and point-by-point in a scanning station of the printer. From the scan signals, density values for exposure time determination in three partial colors and details on the image field number of the scanned negative can be obtained, and these data are stored in a memory, coordinating the determined three partial exposure times with the corresponding image number. All negatives of the copy film strip are exposed successively on photographic paper on an enlarged scale, using the determined exposure times. In a further step, a number of successive negatives of the film strip are exposed on full-scale or reduced scale in matrix form onto a single sheet of said photographic paper.

Abstract: In a photofinishing operation, the correlation of order envelopes, films and the paper prints produced therefrom is carried out automatically. The order envelopes, films and the strip of paper prints are provided with the same machine-readable control number per order. These control numbers are monitored during final processing by machine and, in case of a lack of agreement, the cutting of the film and the paper is prevented and an appropriate alarm is actuated.

Abstract: A method for controlling exposure in the direct printing of color transparencies, the method comprising comparing the neutral density of an original transparency required to be printed with a reference transparency to obtain a measure of the difference in neutral density, this difference then being used to control the exposure time. Control is effected by increasing the exposure time for that portion of the density difference which exceeds a first positive limit by a predetermined amount which is less than the increase in exposure time required by the positive density difference below the first positive limit and decreasing the exposure time for that portion of the density difference which is less than a second negative limit by a predetermined amount which is less than the decrease in exposure time required by the negative density difference above the second negative limit.

Abstract: An exposure control system for color printers having electro/optical means for spectral analysis of different types of original material for printing to determine different spectral coefficients for each material. Each coefficient is classified according to a reference range of values, each range being associated with a different original material. Photoelectric means are provided to determine the color densities of an original and a store stores sets of exposure parameters, each set being associated with a different original material. Automatic selection means responsive to the classification is provided to select whichever parameter set is associated with a coefficient reference range in which the coefficient has been classified during classification.