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J. Marc Gaanon
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Seminaire de Sherbrooke Sherbrooke. Quebec. Canada
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Monochromatic Color with Black and White Slides
TOpromote interest in "slide shows," we mix color slides with black and white. When it is essential to the subject we use commercial color processing, h u t most of our color slides are prepared from black and white transparencies where the black silver imaee " is redaced bv a color oreanic imaze. Since nnlv one color can be fixed in one operation on a given slide, we call the Drocess "monochromatic chromoeenic develooment." w e have adapted a n old techniqu'puhlished Aany years ago in the British Journal of Photography Annual.' At first, this technique seems t o ask for a n awful lot of chemicals and t h e procedure appears t o he burdensome. But, after the first lot of solutions has been prepared and a few trials have been made t o standardize the o~erations.the whole Drocess hecomes very attractive. T h e range of colors is almost limitless and the slides are crisp, especially with high contrast copy film and Kodak fine grain positive film. This process can be used with most photographic material. Use any already processed black and white slide and, if it is dry, let i t soak in water for a few minutes hefore initiating the treatment. T h e temperature of the baths is not critical (around 20°C) and t h e processing can he done in subdued daylight or artificial light.
Bleach Bath. Potassium ferricyanide, 50 g; potassium bromide, 20 g; and water, to make 1I. Chrornoeenic Deuelooec5 Port I: Water. 75 ml:. sodium rnetahirulfire. 5.g; diethyl-p-'phenylenedinmine monohvdrnch~oride.~ LO g; nnd water lo make 100 ml. Pwr 2. Water, 600 ml;scdium carbonate, mmohyd. 20 g; sodium iormaldehvde sulfoxylate, 5 g; potassium bromide, 1g; and water, to make 11. Just before use, mix together: 3 p a of chromogenicdeveloper part 1; 100 parts of chromogenic developer part 2; and 10 parts of color coupler (see below). Color Couplers: Magenta: p-Nitrophenyl acetonitrile," 0.5 g; and alcohol, 100 ml. Yellow: 45-Dichloro acetoacetanilide,82 g; and alcohol, 100 ml. Blue: l-Naphth~l(alpha),~ l g; and alcohol, 100 ml. These couplers can be mired together to obtain nearly any shade of color. Fixing Bath: Sodium thiosulfate, 200 g; water, to make 11. Just before use, mix 7 parts of above fixing bath with 3 parts of bleach bath.
Processing Step I. Bleach image in bleach bath till no further change is noticed (1-5 min). Step 2. Wash in running water for 15 m h 2 Step 3. Color develop in prepared h m o g e n i c developer for 5 min with continuous agitation.3 Step 4. Wash in running water for 20 mim2 Step 5. Treat with prepared fixing bath till no further image change is noticed (1-5 min). This bath is used if only the organic image is wanted. Without this bath both the organic and the silver images will appear on the slide. Steo 6. Wash in runnine" water for 20 - mim2 Step 7. Trent with a wetting agent (e.g.. Kodak Photo.Flo) and dry. N c r e The same procedure c l n h~ applied tu a paper print hut it
'British Journal Photography Annual, 1966-1967, Henry Greenwood & Co. Ltd, London. The washes can be shortened if a film is treated instead of a print and the wash bath has adequate water change. Far individual processing of 35mm slides (24 X 36 mm). 100-ml beakers can be used as baths, a beaker for each color desired. W e tried, with success, Kodak Opal and Ilford nfo Brom. Dissolve each chemical completely hefore adding the next one and follow the order given. The sulfate can be substituted hut not the free base. 'Or 1 g of 3-methyl-l-phenyl-2-pymlin-5can he suhtituted. Or 1g of 2'-chloroacetoacetanilide can be substituted. Or 1 g of 2,4-dichloro-l-naphthol can he substituted for a bluegreen coupler.
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604 / Journal of Chemical Education
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may be necessary to fog the emulsion by exposing it for 1 min to a IW-W lamp at 1 ft, before color developing in chromagenic developer. Some types of photographic papers respond poorly to this techique? Formulas .-.
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