The Relation of the Contact Screen to Picture Quality.

The function of the contact screen in making halftones is described in terms of the light-intensity distribution pattern produced on the emulsion. The relation of this pattern to tone reproduction is explained. The color and dot-shape properties of contact screens are discussed. Also, the effects of auxiliary exposures are shown, and a number of problems encountered in using screens are discussed. The design of screens for making halftone negatives and positives is considered.