Color printing paper must be handled and processed in complete darkness because color paper is panchromatic. Like color film, time and solution temperature is much more critical than in black-and-white processing. Because the processing of color paper must be very consistent, color prints are not processed in trays. Color paper is always processed in automatic color print processors (fig. 12-6) or rotary drum processors.

The chemistry most commonly used in the Navy for color paper processing is Kodak Ektacolor RA Chemicals for Process RA-4. The RA-4 process is a washless process that consists of color developer, bleach/fix, and stabilizer. The total processing time for the RA-4 process is about 4 1/2 minutes.

MAKING TRANSPARENCIES FROM COLOR NEGATIVES

You can make brilliant color transparencies from color negatives as easily as you made color reflection prints by using color printing materials on a transparent film base. These transparencies are of excellent quality. This allows you the option of making them larger, smaller, or the same size as the original negative.

Several materials are available for making color transparencies from color negatives. Two of the most common are Kodak Duratran RA and Kodak Duraclear RA display materials. These materials allow you to make large-display transparencies from color negatives.

The Kodak Duratran RA and the Duraclear RA transparency materials can be printed using the same methods, printing equipment, and processing chemicals as Duraflex RA print paper. Both the transparencies and paper are processed using Kodak Ektacolor RA-4 chemicals; however, the transparency materials require a longer processing time. The Kreonite Model KCP-16 allows for this longer processing time. By flipping a switch, you can slow down the processor, allowing for a longer processing time.

When printing color transparency materials, you must use a black easel. Because these materials do not have a paper backing, light is transmitted through the material and reflects back when a black easel is not used. All other printing steps are the same in printing color paper and color transparency materials. Consult the Photo-Lab-Index for starting exposure and filter pack settings.

COLOR PRINTS FROM COLOR TRANSPARENCIES

Color prints can be made directly from color transparencies (slides) without the time and expense of making an internegative, but the quality of a print can only be as good as the quality of the transparency from which the print is made. Originals that are poorly exposed or processed or are damaged or dusty do not provide satisfactory prints.

Transparencies that are old or stored under adverse conditions are likely to fade to some degree. This fading may not have been equal overall. That can create problems in printing. Generally, slide duplicates vary widely in quality and do not make high-quality color prints.

There are several direct positive materials available for making color prints directly from color slides. Kodak Ektachrome 22 paper is a reversal color paper that, when exposed to a slide, produces a positive color image of the slide. Kodak Ektachrome 22 paper is processed in Kodak Ektachrome R-3000 chemicals. Consult the Photo-Lab-Index for the most updated information concerning these processes.

Another way to make full-color prints directly from color transparencies is by the dye destruction color process. At the time this training manual was written, Cibachrome products are the only direct positive color materials manufactured using this process.

Cibachrome silver-dye-bleach materials consist of a white opaque support, coated with light-sensitive emulsion layers on one side and a matte, anticurl gelatin on the opposite side. This white pigmented plastic film base has a similar appearance to paper but is actually a film, much like color slide materials-the emulsion layers are arranged in the same order as color transparency (slide) materials (including the yellow filter layer).

Unlike conventional color paper processes where dyes are formed from color couplers during processing, dyes in Cibachrome materials are incorporated in the blue, green, and red light-sensitive layers during manufacturing. These cyan, magenta, and yellow dyes are designed to be destroyed when processed. Red exposure is intended to cause the destruction of cyan dyes, green exposure leads to the destruction of magenta dyes, and blue exposure sets up the destruction of yellow dyes.

The processing of Cibachrome materials involves four chemical steps: black-and-white developer, bleach, fixer, and stabilizer. In the black-and-white developer, the exposed silver halide crystals are reduced to metallic silver. When the silver halides in the emulsion layers are converted to metallic silver, the dyes present in the emulsions are fragmented. In the bleach, the silver image is converted back to silver salts

(halides), and the dye fragments are made either colorless or water soluble. The unwanted silver salts (halides) are then removed in the fixer. The stabilizer keeps the remaining color dyes more permanent.

The principles of making color positive prints from color transparencies are the same whether coupler development or dye destruction materials are used. Colored filters are used to alter the printing light to obtain proper color balance, much the same as is done in printing color negatives.

You must keep in mind, however, that you are working with color positive materials, and not negative materials. The borders of these positive materials are black when unexposed. Dust particles and scratches also appear black. To make a test print lighter, you must increase the exposure. Dodging darkens selective areas of a print, and burning in lightens selective areas of a print. Color corrections are performed the same as the visual appearance requires.

AUTOMATED PRINTERS

Many Navy imaging facilities have automated printers that print photographic negatives. Most can be used to print both black and white and color. When high-volume production is routine in an imaging facility, automated printers are an invaluable piece of equipment.

There are many types of automated printers throughout the fleet. Some types hold long rolls of photographic paper that must be taken out and processed through a processor. Other more sophisticated types analyze, expose, cut, process, and dry the paper automatically.