Description: V-mail operation in the field at APO 929. "View of the continuous enlarger on which the image on the film is enlarged to regular V-Mail size of 4¼ x 5 inches. Sensitized rolls of paper, 825 feet in length are used. Here, the operator is adjusting the voltage to secure proper exposure. This is determined by consulting a chart which suggests certain voltage and lens aperture settings for any given film density. " Port Moresby, Papua New Guinea.