Technicolor News & Views (April 1955)

Successful printing of 35mm color motion picture film requires experience and lab- oratory skill. Faulty prints wipe out accu- rate color values achieved in photog- raphy and production. Color printing procedures begin with white light. Optically speaking, white light consists of three primary colors — blue, green and red. This is one way of saying that when proper amounts of blue, green and red light are subtracted from white light, any color visible to the human eye will be produced. Negatives used in color motion picture photography separately record the red, blue and green aspects of the scene. After development, negative images may be silver (black and white to the eye) or dye-colored. Only TECHNICOLOR laboratories prepare dye-transfer release prints from both kinds of image. DYE-TRANSFER RELEASE PRINTS Developed negatives are evaluated to determine the printing light required. The negative is then run through a matrix printer, a device in which special matrix film is exposed by light coming through the negative. Matrix means what it does in other forms of printing—a relief image from which multiple copies are made. After printing, the matrix is developed and etched to produce a colorless gelatin relief image — the positive of the nega- tive from which it was printed. A matrix is prepared for each color aspect of the scene. While the matrices are being made, a special dye-receptive blank film is pre- pared. If the customer wants prints with optical sound tracks, the silver sound rec- ord is incorporated in the blank film at this stage; if the customer's prints are to carry magnetic sound tracks, the silver sound record is omitted and the magnetic tracks are applied after the dye transfer. The matrix film carrying the blue as- pect of the scene passes through a yellow dye solution. It absorbs the yellow dye, and is then brought into contact with the blank film on a dye transfer machine. While the two films are traveling in contact, the yellow dye from the matrix is transferred to the blank film. At the end of the dye transfer machine the first matrix is removed. The blank is now brought into contact with the second matrix, which corre- sponds to the red light in the scene. The second matrix has been traveling through a cyan (blue-green) dye solution, and the dye is transferred to the blank which is carrying the yellow image. After the blank has imbibed cyan and the second matrix has been removed, it is brought into contact with the third matrix, which corresponds to the green Current Zeckniques of 35mm DYE TRANSFER PRINT FROM COLOR NEGATIVE Here a scene is recorded on color negative from which matrices are printed and subsequently dyed. Where cyan dye is present, red light will be subtracted from the scene. No cyan dye is present in the area of the red walls of the barn. Magenta dye will subtract green light — no magenta is present in the green grass area. Yellow will subtract blue light; note its absence in the blue sky portion of the picture. SILVER SEPARATION NEGATIVES DYE TRANSFER PRINT FROM SEPARATION NEGATIVES The same ideal scene (as above) is photographed on silver separation negatives. Three negatives are exposed simultaneously in a special three-strip camera. Silver (black and white) negatives are developed. Matrices made from these negatives are similar to those shown above and perform the same function. Dyes are transferred to the gelatin blank after optical sound track and silver frame lines have been printed onto and developed in the blank. — FOUR —