Chapter 4.

Other Applications of Solarization

Solarization of Color Emulsions

Most of the color films and papers that can be processed by amateurs are based on silver halide emulsions. Therefore they can be solarized in essentially the same way that black- and- white materials can.

The equipment used for black- and- white solarization can also be used for solarizing color materials, but the light bulb for making the Sabatier exposure should be replaced with a safelight fixture (or similar "light box") that can be fitted with various colored plastic filters. This light source typically contains a 25- watt bulb and is suspended about 3 feet over the developing tray. This fixture, together with a set of colored filters, can be used to produce Sabatier densities in a wide variety of colors, in contrast to the gray or black densities formed in black- and- white solarization. Some inexpensive colored plastic sheets, obtainable from stationery stores or theatrical supply houses, are colored strongly enough to be used as filters. Photographic color printing filters (available in cyan, yellow and magenta) can also be used, but these filters are usually too pale to give nice, rich colors in the final print. However, some safelight filters (for example, the yellow Kodak OA filter) give good results.

If the color film or paper is of the reversal type (i.e., if processing gives a direct positive result, without involving a separate negative) the first processing step is essentially an ordinary black- and- white development. The silver halide that has been exposed to light to which it is sensitive is reduced to silver. This development is generally followed by a fogging development of the remaining silver halide, in which dyes are deposited such that the final color matches that of the original exposure.*

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* The Ilfochrome process is an exception; the dyes are incorporated into the emulsion at the time of manufacture. The development is followed by a dye bleach step in which dyes in the vicinity of developed- out silver are destroyed.

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If the color film or paper is of the negative type, there is only one development step. During this step, silver halide reduction is accompanied by a deposition of dyes that have a color complementary to that of the exposure light.

Some of the chemicals used in color processing are more corrosive than those used in black- and- white processing. Hence, although many darkroom workers get away with the use of their bare fingers in the manipulation of black- and- white materials during tray processing, this practice is discouraged in the tray processing of color materials. One should seriously consider the use of tongs or surgical- type gloves during the color solarization processes described in this section.

In the following paragraphs I shall describe procedures for solarizing various color materials. Many variations of these procedures are possible. Obviously the color and intensity of the Sabatier exposure can be varied and must be optimized by trial and error. Typically, the Sabatier exposure time falls in the range 0.5 to 5 seconds. Because one need not be concerned with true color balance, but only with achieving pleasing results, it is possible to falsify colors in the initial exposure. For example, in the case of film exposed in the camera, colored filters can be attached to the lens when making the original exposure. In the case of paper exposed under an enlarger, colored filters can be put in the light path, preferably between the light source and the condenser lens or the ground glass diffuser. The magnitude of the initial exposure, made either in the camera or under the enlarger, can be varied. Decreasing this exposure increases the fraction of the picture colored by the Sabatier exposure; increasing the exposure decreases the fraction of the picture colored by the Sabatier exposure. The time at which the Sabatier exposure is made during the first development can also be varied. That is, the ratio of pre- Sabatier development to post- Sabatier development can be varied. Clearly, with all these variables available, there are many opportunities for creative expression.

It is even possible to make a color solarization from an ordinary black- and- white negative. For example, the negative image can be enlarged with colored light onto a sheet of color paper (either reversal or negative paper), and the print can then be solarized with another colored light during processing, yielding a 2- color photograph.

Finally, colored solarizations can be prepared by a method in which the solarization does not take place during the development of color emulsions, as we have been discussing, but rather during the development of black- and- white transparencies (negative or positive). Several of these solarized transparencies are then used as masks during the stepwise exposure of color film or paper, which is then processed normally. We shall discuss this unusual method elsewhere, under the topic of posterization.

Reversal Processing

In reversal processing, the first development is selective; that is, only silver halide grains that have been rendered developable by the initial exposure are reduced. Thus solarization can be carried out during this development step, much as in ordinary black- and- white solarization. However, the second development*

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* In Ilfochrome processing, to be discussed separately, there is no second development.

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is a fogging color development, and solarization is not feasible at this point because all of the silver halide grains remaining in the emulsion are reduced in this step, even with normal processing. In fact, room lights can be turned on during the second development, and so a Sabatier exposure during the second development would obviously be pointless.

It is mainly into the black or deep shadow regions of a reversal slide or print that color is introduced by solarization. These regions, of course, are undeveloped during the first development. They acquire the color of the light used during the Sabatier exposure and, at least in the case of films, are often surrounded by black Sabatier border lines.

Color Reversal Film Processing.-

The processing of Kodachrome films (the K- 14 process) is relatively complicated and can be carried out only in licensed laboratories with special equipment. Thus, although in principle one can solarize Kodachrome, the ordinary photographer cannot do so. The most popular direct- positive films that can be conveniently processed without specialized equipment (using process E- 6) are Ektachrome, Agfachrome, and Fujichrome. Process E- 6 chemicals, such as those in Kodak's convenient Hobby- Pac color slide kit, are available from many photographic suppliers.

I have had success in the solarization of 35- mm Ektachrome 100 Plus film that was exposed using the normal, recommended exposure index of 100. Ten- inch lengths of the exposed film were clipped to a black plastic lath, and processing was carried out in trays, using Hobby- Pac chemicals, with temperatures in the neighborhood of 21oC. In a typical run, a Sabatier exposure of several seconds was made after the film had been in the first developer for about ten minutes; the film was allowed to remain in this developer for a further sixteen minutes (or a total of 26 minutes, corresponding to Kodak's recommendation for the "first developer" time).

The remainder of the processing, after the first development, proceeded according to the Kodak recommendations for normal E- 6 processing. Room lights could be turned on after the wash following the first development, and so the procedure was not particularly onerous. See Table 4.1 for an outline of the E- 6 processing steps.

Table 4.1 Solarization by Tray Processing of Ektachrome Film (E- 6 Process)

1. First Developer: In complete darkness, 21oC, total time 26 min. for fresh developer. The Sabatier exposure can be made between 7 and 18 min. after the start of development.

2. Wash: In complete darkness, 20- 30oC, for about 2 min., in running water.

The following steps can be carried out in normal room light.

3. Color Developer: 21oC, for 9 min., if developer fresh.

4. Wash: 20- 30oC, for about 2 min., in running water.

5. Bleach- Fix: 20- 30oC, for at least 10 min.

6. Final Wash: 20- 30oC, for at least 4 min., in running water.

7. Stabilizer: 20- 30oC, for at least 1 min.

8. Dry: Hang the film in a dust- free place. Evaluate color and density only after the film is dry.

Fig. 4.1 A University of California, Berkeley, campus scene. Ektachrome 100 solarized with a red light. [c/r W. L. Jolly.]

Very brief discussions of the solarization of color reversal films can be found in the literature.8,108,174 This general solarization method is not very popular when applied to color reversal film that has been given the original exposure in the camera. The reason is obvious: if any mistake is made in the solarization process, the picture may be ruined and the opportunity to retake the picture may be lost forever. Consequently it is a commoner procedure to carry out the solarization process when making duplicates of color slides.

Color Reversal Paper Processing, Chromogenic.-

Agfachrome, Ektachrome, and Fujichrome reversal papers are designed for making color prints from color transparencies and can be processed using the relatively simple R- 3000 process or its equivalent. This process, like the E- 6 process for Ektachrome, involves an initial black- and- white development during which solarization can take place, and a fogging color development during which solarization is impossible.

The Beseler 3- Step process (#8990) for developing Ektachrome 21, 22 and 23 color papers is economical and allows room- temperature processing. Good results can be obtained using the procedure outlined in Table 4.2.

Table 4.2 Solarization by Tray Processing of Ektachrome 22 Paper with the Beseler 3- Step Kit Chemicals

1. First Developer: In complete darkness at 20oC. Total time 4.25 min. The Sabatier exposure can be made between 1.5 and 3 min.

2. Wash: In complete darkness at 19- 22oC, for 4 min. in running water.

The following steps can be carried out in normal room light.

3. Color Developer: 19- 22oC, for 5.75 min.

4. Wash: 19- 22oC, for 30 sec. in running water.

5. Bleach- Fix: 19- 22oC, for 5.5 min.

6. Wash: 18- 23oC, for 4 min. in running water.

7. Dry: As appropriate for a resin- coated paper.

Fig. 4.2. Christos Redentor, Rio de Janeiro. Ektachrome 22 paper solarized with an orange light. [c/r W. L. Jolly.]

Fig. 4.3. St. Malo houses. Ektachrome 22 paper printed using a black-and-white negative (white light in enlarger) and solarized with a blue light. [c/r W. L. Jolly.]

Color Reversal Paper Processing, Non- Chromogenic (Ilfochrome).-

Ilfochrome color prints are made from color slides by a process different from that used with chromogenic papers. After the enlarger exposure and essentially a black- and- white development, a bleach causes destruction of the dyes in the vicinity of the developed silver grains, leaving in place a positive dye image with colors corresponding to those of the initial exposure. A fixer then removes all the silver halide remaining in the emulsion.

Solarization of Ilfochrome is simple. Inasmuch as the total development time is only 4 minutes at a temperature of 20oC, tray processing is not at all tedious, and I recommend it in spite of the manufacturer's claim that tray processing should not be used.

When Ilfochrome- A II paper (with either a glossy or a "pearl" finish) is processed with P- 30 chemicals, the procedure outlined in Table 4.3 can be used for dramatic solarizations.

Table 4.3 P- 30 Solarization Processing Steps for Ilfochrome in Trays

1. First Developer: In complete darkness, 20oC, total time 4 min. The Sabatier exposure can be made between 1 and 3 min.

2. Wash: In complete darkness, 20- 30oC, for 30 sec., in water.

3. Bleach: In complete darkness, 20- 22oC, for 4 min.

4. Fixer: In complete darkness, 20- 22oC, for 4 min. The normal room lights can be turned on after about 1 min.

5. Final Wash: 20- 30oC, for 4 min. in running water.

6. Dry: Dry either clothesline- style or with the aid of a hair dryer set at low heat.

It is not necessary to use the Ilfochrome fixer and developer.105 A solution of 250 g. of sodium thiosulfate (Na2S2O3.5H2O) and 15 g. of anhydrous sodium sulfite (Na2SO3) in 1 liter of water can be used as the fixer. For the developer, use Kodak Dektol diluted 1+2 with water, and add 7 mL of the fixer to each liter of the diluted Dektol.

Fig. 4.4. Sports car and owner. Cibachrome paper solarized with an OA yellow safelight. [c/r W. L. Jolly.]

Negative Processing

In color negative processing, the first and only development causes reduction of the silver halide grains that have been rendered developable by exposure. Thus solarization can be carried out in this step. Simultaneously with the formation of the metallic silver, there is a deposition of dyes having a color complementary to that of the original exposure light. Therefore the Sabatier exposure, which mainly affects the originally unexposed parts of the film or paper, introduces a color complementary to that of the Sabatier exposure light. This solarization color is formed mainly in the regions that would be white, or of very light hue, in a normally processed picture.

Color Negative Film Processing.-

Films such as Agfacolor, Kodacolor, Vericolor, and Fujicolor are negative films that can be processed by the relatively simple C- 41 process. Chemicals for this process are available in kits in photographic supply stores. Films of this type that are designed to make negatives which are then used to make prints are relatively low- contrast and have an orange film base. It is better to solarize so- called print films, such as Kodak Aerial Ektacolor Print Film 410974 and Kodak Vericolor Print Film 4111.249 These are relatively high- contrast films, ordinarily used for making positive transparencies from negatives, that are available in sheet form and thus can be tray- processed.

Zakia249 recommends the following procedure:

1. Enlarge a color slide onto Vericolor Print Film.

2. Develop for 1.5 minutes with agitation.

3. Remove the film from the developer and allow it to drain for about 20 sec.

4. Place the wet film under a colored light source and make the Sabatier exposure. (The film is removed from the developer tray for this exposure because the C- 41 developer is not a clear solution.)

5. Return the film to the developer for 2 minutes.

6. Continue with normal C- 41 processing.

The result is a solarized negative transparency. If you want a positive rendition on paper, print this negative onto a color negative paper such as Ektacolor paper.

Color Negative Paper Processing.-

Agfacolor, Ektacolor, and Fujicolor papers are a few of the many negative- type papers that can be processed by the simple EP- 2 or analogous process. I have had success in the solarization of Ektacolor Plus paper with both the Kodak Hobby- Pac color print kit and the Beseler 2- Step Color Print Processing Kit. When the processing is carried out in trays at room temperature, a tedious 17- minute developing time is required with the Kodak chemicals, whereas a more reasonable 9- minute developing time can be used with the Beseler chemicals. The procedure recommended for solarization with the Beseler kit is given in Table 4.4. If normal color balance in the unsolarized part of the print is desired, a filter pack of 40M + 40Y is recommended for a white- light enlarger.

Table 4.4 EP- 2 Solarization Processing Steps for Ektacolor Plus Paper in Trays with Beseler 2- Step Processing Chemicals

1. Developer: In complete darkness, 20oC, total time 9 min. for fresh developer. Sabatier exposure made sometime between 3 and 7 min.

3. Stop Bath: In complete darkness, 17- 24oC, agitate for 30 sec. in a 2% acetic acid solution.

4. Bleach- Fix: At 19- 24oC, for 3 min. Room lights can be turned on after the paper has been in the bleach- fix for several seconds.

5. Wash: 17- 24oC, for 6 min., in running water.

6. Dry: Dry as appropriate for a resin- coated paper.

Fig. 4.5. Ektacolor Plus paper solarized with a green light. [c/r W. L. Jolly.]

The reader is referred to the book by Walker and Rainwater238 for further discussion of the solarization of prints from color negatives.

It has been reported6 that a color negative print was solarized by giving the paper an enlarger exposure suitable for making a straight print and then putting the paper face up in a tray of "aged" (well- used) color developer. After 2 minutes of development, a 15- watt nightlight clamped 2 feet above the tray was turned on for 4 seconds. The print was developed an additional 2 minutes, bleach- fixed, washed, and dried normally. The resulting image was quite pleasing, showing light Sabatier border lines and a magenta color in areas that would otherwise have been bluish- white. Unfortunately the photographer was unable to duplicate the process during the same printing session, probably because of the non- reproducible character of the "aged" developer used.

Duotone Solarization

Black- and- white prints made with different kinds of paper often have silver images with different tones, or colors. These differences in tone can be rather subtle and difficult to detect when individual prints are viewed in isolation, but when prints on different kinds of paper are examined next to one another, the tonal differences become much more obvious. Some prints have what appear to be blue- black images; others, on "warmer" papers, have brown images. The photographer can choose a paper that has a tone appropriate to the subject matter for each of his pictures. However, the image tone is not only a function of the paper, but also of processing variables such as the choice of developing agent, its concentration, and the bromide concentration of the developer. For example, one can warm the image tone of a paper by going from a metol- only developer to a dilute hydroquinone- only developer or by increasing the bromide concentration of the developer. Recipes for achieving various tones by modification of the development conditions are given by Haist.101

A typical solarized print consists of two parts - (1) the normally- developed, positive, image that forms during the first development stage, and (2) the image (either negative or of uniform density) that forms during the second development stage (that is, after the Sabatier exposure). These two parts of the print have the same tone when the two developments are carried out in the same developer. However, when the second development is carried out using a developer suitably different from the first developer, the second image can have a tone markedly different from that of the first image. We shall discuss specific applications of this idea to solarization.

Duotone Solarization.139 -

Essentially two- tone solarization can be accomplished by carrying out the development in two successive baths, with the second developing bath formulated to give a slightly brownish tone to the print after the Sabatier exposure. The following recipe is suggested as a starting point for experimentation, using Agfa Brovira paper.

For the first developer, use ordinary 1:1 Solarol. For the second developer, use 1:1 Solarol which has been modified by the addition of 36 g of potassium bromide (or 31 g of sodium bromide) per liter of the diluted developer. Leave the print in the first developer for about 45 seconds, transfer it to the second developer, and, after 10- 15 seconds of vigorous agitation, make the second exposure and continue development for a further 60 seconds or so. A fairly intense second exposure of 5 seconds to a 100- watt light bulb at 4 feet is recommended.

This procedure gives second- image tones that are definitely warmer than the first- image tones, and is quite satisfactory for producing subtle duotone images. However, a much more dramatic difference in tone can be achieved by following up this bromide duotone solarization with chemical toning. (See Toned Duotone Solarizations, below.)

Fig. 4.6. A duotone-solarized print made using a high-bromide second developer. Notice the difference in tone between the first and second images. [c/r W. L. Jolly.]

Toned Duotone Solarizations.131 -

In this general procedure, the relatively subtle tonal differences produced by duotone solarization are made more dramatic by subsequent chemical toning.

We have already pointed out that a change in tone associated with a change in the composition of the developer is caused by a change in the size and shape of the silver grains that form during the development. The silver particles are usually smaller in colored images than in black images. The chemical reactivity of a solid generally increases with increasing surface area, so the finely divided grains of a colored image are more reactive than the relatively large grains of a black image. Therefore, one expects a colored second image to undergo chemical toning more readily than a relatively black first image. Indeed, I have found this to be the case, at least for selenium and sulfide toning. Solarization with a high- bromide second development combined with a final chemical toning produces much more dramatic solarized prints than can be produced by the high- bromide duotone process alone. The chemical toning is largely restricted to the second image, formed during the second development stage. Thus the finished print consists of one part with a full range of neutral tones, from black through greys to white, and another part with a range of brown or yellow tones. The results can be quite striking.

I shall first describe the materials and procedures for processes that end with selenium toning, because the selenium toning bath is easier to prepare and more pleasant to work with than the sulfide bath.

Materials -

For the first developer, use Solarol, diluted 1:1. For the second developer, use Solarol, diluted 1:1, in each liter of which 36 grams of potassium bromide or 31 grams of sodium bromide is dissolved. With this second developer, the final second image (i.e., the second image after subsequent selenium toning) usually has a rich orange- brown tone. If a lighter, yellower, second image is desired, add more bromide (say, 50 grams of potassium bromide per liter) to the second developer. If a darker, reddish- brown, second image is desired, add less bromide, but be warned that the final tones of the first and second images are very similar when the bromide content of the second developer is reduced below about 6 grams of potassium bromide per liter.

For the toner, use Kodak Rapid Selenium Toner, diluted 1:7. For the paper, use Agfa Brovira (glossy), grade 4 or 5, or BroviraSpeed, grade 4 or 5.

Procedure for Agfa Brovira -

Follow the directions for controlled duotone solarization. If a relatively low bromide concentration is used in the second developer, a less intense second exposure can be used; a higher bromide concentration will require a more intense exposure. When a satisfactory second image has formed, transfer to the stop bath and fix as usual, and wash thoroughly. Transfer to the selenium toner and agitate until a satisfactory tone is achieved in the second image. The full color is sometimes not reached until after 5 or 10 minutes in the toner. Finally, wash thoroughly and then dry in the usual way.

Procedure for BroviraSpeed -

The development and washing times are considerably reduced for this RC paper. A first development time of about 40 seconds, an agitation period in the second developer (preceding the Sabatier exposure) of 10- 15 seconds, and a second development time of about 45 seconds are satisfactory. Because of the higher sensitivity of BroviraSpeed, the Sabatier exposure can be less intense. However, the time required for the final toning seems to be about the same as that for Agfa Brovira.

Fig. 4.7. The result of selenium-toning a duotone print like that of Fig. 4.6. [c/r W. L. Jolly.]

Fig. 4.8. A selenium-toned duotone-solarization prepared like Fig. 4.7, except that, in the initial duotone processing, the second developer was even more concentrated in bromide. [c/r W. L. Jolly.]

Other Toning Processes -

I hoped that this general method could be extended to other toning processes, such as those based on an initial oxidation of the silver by ferricyanide. Thus I have tried final tonings using the bleach/sulfide and the Prussian blue methods, but without marked success. Pleasant toned prints are obtained, but the tone is not completely restricted to the second image. Apparently the reactivities toward ferricyanide of the silver particles in the two parts of the solarized prints are similar.*

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* However, Mack172 has found that even ordinary solarized prints can be selectively sepia- toned in the second image.

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Most of the Berg Color Tone dyes also give similar tones to both the first and second images. However, the Berg yellow dye gives the first image an olive- drab tone and the second image a yellow- brown tone. This combination is useful for coloring solarizations of wooded scenes with considerable sky area.

Kodak Poly- Toner, which contains both selenium and potassium sulfide, gives results similar to those obtained with plain selenium toner, and there seems to be no special advantage in using this toner. However, Kodak brown toner, which is simply an alkaline solution of potassium sulfide, gives somewhat yellower tones than the selenium toner and does not require as much bromide in the second developer to obtain comparable colors in the toned image. If Kodak brown toner is used, I recommend that it be used at a 1:10 dilution at about 27oC for a period of 15- 20 minutes. The concentration of bromide in the second developer can be about one- half of that used with selenium toner. Thus 4 grams of added potassium bromide per liter gives a dark brown tone, and 50 grams gives a light almond tone.

Line Drawing and Outlining

When a print is made from a rather contrasty negative by Sabatier development with a heavy Sabatier exposure, the resulting print consists mainly, if not entirely, of white Sabatier border lines. The picture looks like a white line drawing on a black background. If this print is then used as a paper negative to make a second print, the resulting "second generation" print is a black line drawing on a white background. (Of course, the latter image is a mirror image of the original unless the negative is flipped when making the initial print.) Obviously this procedure can be abbreviated if the original negative, instead of the first print, is solarized. Then the first print is a black line drawing on a white background.

Many of Man Ray's solarizations had the characteristics of line drawings. However, none of his prints had pure line- drawing character; they always retained some degree of continuous- tone character. Stevens and Norrish222 appear to have been the first to completely eliminate continuous- tone character from solarizations. Here is the procedure they reported in 1936: "A photograph is taken of a light object against a black background and the plate is fully developed. It is then given a short rinse in the dark, is exposed to diffuse light and redeveloped. If the first and second exposures have been correctly adjusted the image of the object will have undergone little change since the first development, and will be surrounded by a sharp white line, and outside that a black background. When the negative is printed the subject appears surrounded by a black line on a white background. Besides being capable of considerable artistic treatment, such photographs might also be conveniently used for the illustration of certain botanical and zoological specimens, and also for photo- micrographs."

Fig. 4.9. Border line prints of Stevens and Norrish. [From ref. 222.]

In the early 1940s, Wynn Bullock became aware that nobody had ever published any of the detailed procedures for controlling the solarization process. He spent six or seven years working in his spare time on the process, much of this time spent on attempts to patent the procedure he worked out for making line drawings. Although the Patent Office repeatedly pointed out that his work had been preempted by other workers, Bullock persisted and even went to Washington to appear before the appeal board. Finally, in spite of the clear precedence of Stevens and Norrish, the board granted him a patent for his "Photographic Processes for Producing Line Images," in which he essentially elaborated on the Stevens and Norrish process.39 Granted, Bullock did emphasize a point not made by Stevens and Norrish, namely that line thickness can be controlled by the sharpness or softness of focus of the object being photographed. That is, for a very fine line, the focus must be very sharp; for a wide line, the focus must be relatively fuzzy.

Fig. 4.10. Border line prints of Bullock. [From ref. 39, p. 15.]

Several workers have used solarization to produce black outlines in continuous- tone renditions of placental cells,232 bones,207 and various metal parts and utensils.38,40 One way of producing this continuous- tone/black- outline combination is a single- negative method, in which the contrast and exposure are adjusted so that much of the developed negative image has normal negative character and so that the Sabatier border line forms in the regions that ordinarily would be shadow regions, of low density in the negative. In other words, the negatives are similar to those of Man Ray that gave prints with normal- looking subjects but with black- line borders. A second way of producing the effect, endorsed by Bullock,38,40 is a two- negative method, in which the images of a normal negative and a solarized negative with only white Sabatier border lines are carefully superimposed on photographic paper. Bullock claimed that the methods for producing continuous tone images with black borders were covered by his patent, but he granted use of the methods for amateur work and for medical illustrations without fee. It is unfortunate that Bullock spent a great deal of time patenting his procedure. He probably never got much remuneration for his efforts, and if he had spent that time writing up the methods required to control the process in more detail than was allowed in the patent, other photographers would have benefitted more.

Many other workers, only a few of whom are cited here,53,58,59,84,91 have described the making of line drawings by solarization. Almost unanimously they have recommended the use of high- contrast film such as Kodalith. However, almost as good results can be obtained by using very high contrast papers and the paper negative method. Resin coated papers, such as BroviraSpeed, grade 5, are particularly useful because the sheets have little tendency to curl when dried and therefore make good contact with one another during the contact printing step of the paper negative process. If an attempt to make a line drawing gives a print with lines and some residual continuous- tone imagery, the continous- tone material can usually be eliminated by one or more copying steps with high- contrast paper or film.

Fiedler84 has pointed out that if one uses the Sabatier effect when making a copy of an already solarized print with border lines, the copy will have parallel double border lines. Very interesting images can be obtained in this way.*

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* See second- order solarization in the section on isodensitometry which follows.

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Bruguiere80 and Ubac147 produced some striking images, with subjects bordered on one side by narrow "shadows," by combining bas- relief techniques (see Chapter 2) with solarization. One can only conjecture as to the details of their techniques, but it appears that the methods involved the printing of off- register sandwiches of solarizations and either negative copies of solarizations or regular negatives. The method is certainly worthy of further study and development.

Fig. 4.11. Bruguuiere: Bas-relief and solarized head, 1936-40. [From ref. 80, p. 102.]

Craig55 has described an unusual solarization technique which, he claims, gives bas- relief prints. He makes the Sabatier exposure using the enlarger light, with the negative still in place. The shadow areas, thinner on the negative, receive more reexposure than the highlights. Imprecise alignment of the reexposure image on the print causes marked edge effects. This difficult- to- reproduce method is similar to "POP solarization," discussed near the end of this chapter.

Isodensitometry and Color Posterization

Isodensitometry. -

When a sheet of high- contrast film is exposed under an enlarger to a negative image and solarized with an intense Sabatier exposure, the minimum in the H & D curve is at the bottom of a trough, or trench, with rather steep sides. This trough, corresponding to the low- density regions of the solarized transparency, is a "window" spanning a narrow exposure range of the positive image. By appropriate reduction of the enlarger exposure, the window can be made to correspond to the midtone regions of the original scene, and further reduction of the enlarger exposure can move the window into the shadow regions. So we see that solarized transparencies of this type are essentially tone separation masks. Ordinarily, tone separation masks are prepared by a relatively laborious process involving the overlaying of high- contrast positive and negative transparencies. Therefore it is surprising that the simpler solarization method has found only infrequent application, mostly in technical fields where isodensity contour diagrams are useful.157 For example, solarization isodensity contours have been used in astronomy,113,218,236 spectrophotometry,239 photomicrography,158 profile testing,160 radiation physics,236,244 and the study of stress gradients.23,181,211,212,213,230

Fig. 4.12. Ordinary print of the Whipple-Fedtke comet, Feb. 25, 1943. [From Lau and Krug, ref. 157, p. 64.]

Fig. 4.13. Composite print of the comet made from three equidensity pairs. [From Lau and Krug, ref. 157, p. 64.]

When isodensity contours consist of broad lines (caused, say, by a low density gradient in the original image), they may be copied with solarization processing to produce second- order isodensity contours. Each of the two edges of a first- order line yields a line, and so second- order renditions have twice as many lines as first- order renditions. If desired, the solarization process can be repeated again; eventually very sharp lines are obtained.

Color Posterization. -

Tone separation masks are used in non- technical photography to make color posterizations.75,79 Posterization is the technique of separating the tonal gradations of a photograph into clearly defined steps. In effect, a smooth slope is converted into a staircase. There is no need to make tone separation masks in the preparation of black- and- white posterizations, because straightforward high- contrast negatives suffice in this process. However, in color posterization, tone masks are needed so that each density level can be produced with a separate color. Although separation masks prepared by the solarization method are not as clean- cut (i.e., not as good at sharply separating the density levels) as those prepared by the use of high- contrast positive and negative transparencies, they are nevertheless effective in color posterization because the adjacent colors blend into one another, giving more realistic gradations of color.

Color Posterization with Paper Tone Masks. -

Resin- coated photographic paper can be used instead of high- contrast film for making solarized tone masks.140 The lower contrast of the paper allows the adjacent zones to blend even more effectively. We shall here give directions for posterization using such tone masks with color reversal paper.

Most negatives have a range of density that is just about right for making a 4- tone posterization by solarization. The first three tones correspond to (1) the dark black (heavy shadow) regions of the print, (2) the medium dark regions, and (3) the medium light regions. Solarized prints can be used as the tones masks for all three of these density regions, but the mask for the dark black regions can be omitted if it is desired that this density region appear, realistically, black in the final posterization. The fourth tone corresponds to the highlights of the print. An ordinary unsolarized, but very dense, print is used as the tone mask for this density region.

Very little special equipment, beyond that used for solarization, is required. An enlarger easel on which photographic paper can be accurately and reproducibly positioned is necessary, but most darkrooms are already equipped with such an easel, and so this is usually no problem. To expose the color paper through the tone masks, one needs a flat surface with two raised edges at right angles against which the color paper and tone mask can be shoved to maintain consistent alignment, and a piece of plate glass to lay on top of the mask. I have found it convenient to use a second piece of plate glass as the flat undersurface for the paper sheets; then the tone mask and color paper are sandwiched between two glass plates during the exposures to colored light. A colored light source, such as that described under Solarization of Color Emulsions, is also needed.

The solarized prints which are to serve as the tone masks preferably should be made from Agfa BroviraSpeed #5 paper. The developer used for the solarizations should be Solarol, diluted 1 + 1. The final color print is made with any reversal paper and the corresponding processing solutions. The following directions are appropriate for a 3- color posterization, in which no tone mask is used for the darkest regions of the normal print.

1. Place the negative upside- down in the negative carrier of the enlarger. This is done so that the final posterization is not a mirror image of the desired picture.

2. By trials with small pieces of the enlarging paper, determine the enlarger exposure which gives a very light print with a significant amount of black and grey in it when developed normally for two minutes in 1 + 1 Solarol. We shall call this exposure time T. When this exposure time is increased by a factor of three, to 3×T, the developed print should be very dark, but should still contain an appreciable amount of white area.

3. Expose a sheet of paper for the time T; develop it for 50 seconds; turn on a 100- watt lamp about four feet over the tray for about three seconds, and continue developing for another minute. Treat the print with stop bath; fix; wash, and dry as usual. (If the second image is not black enough, or if the light "window" zone is too dark, appropriately adjust the Sabatier exposure.)

4. Place a second sheet of paper in exactly the same place on the easel, and expose for a time 2×T. Solarize the print exactly as before.

5. Expose a third sheet of paper on the easel for a time 3×T. Develop normally (without the Sabatier exposure) for 2.5 to 3 minutes. To obtain higher contrast in this tone mask, the Solarol developer can be replaced with Dektol or even an extreme- contrast developer such as D- 8.

6. After fixing, washing and drying the three tone masks, choose appropriate colored filters for each of the masks, corresponding to the medium dark, medium light, and highlight regions of the print.

7. In complete darkness, position a sheet of unexposed color reversal paper face up on the printing flat. Place one of the tone masks face down on this sheet of paper, taking care to align two edges of each sheet with the raised guides of the flat. Carefully cover the papers with a sheet of plate glass to press down the tone mask so that it is in close contact with the color paper. Expose the sandwich to colored light. The time of this exposure can be decided on the basis of previous exposures with the color filters or by trial and error.

8. Using the other two tone masks and corresponding color filters, make two more exposures with the same sheet of color paper, as described in step 7. You will probably find it convenient to temporarily store the sheet of color paper in a light- proof box or envelope while you are changing the color filters and the tone masks. Otherwise all the operations must be carried out in the dark. Make sure that the tone masks and the color paper are oriented the same way during the three exposures. If one of the masks is mistakenly rotated by 180o, the resulting posterization will probably be a mess.

9. Place the triply- exposed color paper in the processing tube, and process the print in the normal way.

You will probably want to try several different combinations of colors and exposure times with a given set of tone masks before you are satisfied with the resulting posterization. Don't feel bound to use all three tone masks. If you omit the color exposure for a tone mask, the corresponding density regions of the print will simply appear black. Such a print can be pleasing even if those black regions are the highlights in the normal print.

Fig. 4.14. A color posterization made using solarized prints as paper tone masks. [From ref. 140. c/r W. L. Jolly.]

Other Color Solarization/Posterization Methods. -

Thadini231 has described, with only few details, what he calls "color solar- posterization." The process involves taking two litho film solarized masks and contact printing them in register through a color filter on a sheet of color paper. Similar methods are discussed by Gareis and Scheerer89 and Langford.155

Langford156 briefly describes an interesting procedure that could be used to solarize color materials via black- and- white solarization- posterization. First a tone mask is made by exposing panchromatic black- and- white film to a color image through a color filter. The film is solarized. A set of such solarized masks, corresponding to a different color filter for each density range, is then used to make a posterized color print. The print is posterized in terms of colors, not densities.

Direct Positive Black- and- White Transparencies

In a typical solarization of film, the lighter regions of the original scene are produced as a negative and the darker regions are produced as a positive, with a light border between these regions. It is not generally recognized how easy it is, by simply lowering the original camera exposure, to solarize film so as to produce a completely reversed (positive) image, i.e., a direct positive transparency.129 Because this complete reversal is achieved by decreasing the exposure markedly below the value required to obtain a good negative image by normal development, the Sabatier reversal processing effectively increases the exposure index of the film - in some cases by as much as a factor of 16, or by 4 stops.

The discoverer of the Sabatier effect, William Jackson, obtained direct positive transparencies with collodion plates in 1857. Although many other photographers rediscovered the phenomenon during the remainder of the nineteenth century, it does not appear that any of these workers chose to refine the process into a reproducible method both for increasing the effective sensitivity of the photographic plate and for obtaining the reversal required for direct positive transparencies. However, in 1907, J. Peat Millar183 did publish a method designed for "The Saving of Grossly Under- exposed Plates." After he treated an underexposed plate with hot developer for an hour, the plate appeared lightly fogged all over. Then he "took the plate out and held it with the glass side to a gas flame for twenty seconds, then put it back into the developer for some time, where it gradually changed from an under- exposed negative without detail into a seemingly well- exposed positive with plenty of detail. It was then fixed and washed as usual." This general method was not used much for direct positive reversal until the 1940s, when Hans Arens of Agfa developed the method for photographic emulsions with mainly internal sensitivity specks.16 Apparently this latter method did not find much commercial application.

The modern films that give the best solarized transparencies, with clean highlight areas, are extreme high- contrast films such as Kodalith, Technical Pan, and Ektagraphic HC Slide films. Unfortunately these films are so contrasty, even when developed with a low- contrast developer such as dilute Solarol, that the transparencies show some reversal in the extreme highlight areas of scenes with normal luminance ranges. However, good results can be obtained if the films are given a weak uniform exposure to light before the first development. This extra exposure causes the Sabatier H & D curve to shift, as shown in Figure 4.15, so that the direct- positive region extends to a lower exposure region and has a lower slope (lower contrast). If the weak uniform exposure is adjusted appropriately, the effective exposure index is about twice that appropriate for processing without the weak supplementary exposure, and very nice transparencies, with good tonal values, can be obtained.

Fig. 4.15. Sabatier H and D curves corresponding to various levels of supplementary, uniform exposure before the first development. Curve 0 represents no supplementary exposure. Curves 1-6 were calculated for supplementary exposures increasing in order of the numbers. Notice that if the supplementary exposure is too great (as in curves 4, 5, and 6), the desirable minimum is eliminated and reversal is impossible.

Generally metol- hydroquinone developers such as Dektol give substantially higher minimum densities than metol- only developers in solarizations. However, in some cases the hydroquinone provides benefits that somewhat compensate for the increase in minimum density. Thus, when a normal- contrast film such as Tri- X is solarized using stock Dektol as the developer - although the highlights are not as clean as those in transparencies made using extreme contrast films and Solarol - the transparencies have good contrast and the effective daylight exposure index has the phenomenally high value of 6400.

Processing Details. -

The processing of sheet film is carried out essentially as described in Chapter 1. The film is immersed emulsion- side up in a tray of developer, and the tray is vigorously rocked, both back- and- forth and sideways, for 30 seconds. Thereafter, the tray is gently rocked for 3- second intervals approximately every 15 seconds. After the Sabatier exposure, the second development continues with the same intermittent agitation used during the first development. Some films release into the developer a red dye which absorbs some of the actinic light of the Sabatier exposure. In such cases the developer must be replaced frequently, or two- bath development must be used, with the second bath used for the Sabatier exposure and second development. The processing of 35- mm film is also carried out as described in Chapter 1.

Specific exposure and development parameters are given in Table 4.5. In all cases the recommended developer temperature is 16.5- 18.5oC., although other temperatures can be used if the development times are suitably modified. The recommended exposure indexes are approximate; camera peculiarities and slight changes in processing conditions may require adjustment of these values up or down by factors of as much as 2. The Sabatier exposures were generally made with a frosted 60- watt tungsten light bulb (4 ft. from the film) connected to a light dimmer and a darkroom exposure timer, adjustable to 0.1 second. The voltage values correspond to the voltage across the light bulb after previous adjustment of the light dimmer. The listed voltages and exposure times correspond to my particular setup; only the relative values for different films have quantitative significance.

The supplementary weak uniform exposures given the extreme contrast films, like the Sabatier exposures, must be determined by trial and error. However, the following data may be helpful when making the first trial.

Fig. 4.16. A view of Lewis and Hildebrand Halls on the U.C. Berkeley campus. A direct positive black-and-white transparency produced by solarization of Kodalith film. [See ref. 129, c/r W. L. Jolly.]

. Table 4.5. Conditions for Sabatier Direct- Positive Film Processing

Film Exposure Developer Devel. times Sabatier exposure

index (seconds)

Day Tung 1st 2nd Volts Seconds

Kodalith 25 10 1 + 3 Solarol 1.25 4 38 1.6

Kodalith* 50 20 1 + 3 Solarol 1.25 4 38 2.5

Tech Pan,

sheet 400 400 1 + 3 Solarol 1.67 3.5 26 0.4

Tech Pan,

sheet* 700 700 1 + 3 Solarol 1.67 3.5 26 2.0

Tech Pan,

35 mm 200 200 1 + 3 Solarol 1.5 4 30 0.4

Tech Pan, 35 mm* 250 250 1 + 3 Solarol 1.5 4 30 2.0

Ekt. HC,

35 mm 12 10 1 + 3 Solarol 1.25 4 38 2.8

Ekt. HC,

35 mm* 12 10 1 + 3 Solarol 1.25 4 38 5.0

Plus- X,

sheet or 600 400 1 + 1 Solarol 1.5 5 38 1.6

35 mm

Tri- X,

sheet or 6400 4000 Stock Dektol 2 4 28 0.3

35 mm

P3200 10000 Stock Dektol 5.5 6.5 30+ 0.4+

* Film given a supplementary, weak, uniform exposure before development. See text for suggested trial voltages and exposure times.

+ 15- watt bulb at 6.5 ft.

With my setup, the supplementary weak exposure for Kodalith was 0.3 second at 25 volts with a 60- watt bulb at 4 feet; for Tech Pan, 0.3 second at 25 volts with a 15- watt bulb at 8 feet; for Ektagraphic HC slide film, 0.4 second at 25 volts with a 60- watt bulb at 4 feet.

In your first attempts, bracket the camera exposures by at least 1/2 and 1 stop, both above and below the recommended values. If you use 35- mm film, don't develop the whole roll on your first attempt, because you'll probably have to make several adjustments of the Sabatier exposure (and the supplementary exposure, if any) before you consistently get satisfactory results. It may even be worthwhile to go through all the processing steps with omission of the Sabatier exposure. The resulting transparency in that case should be a very thin negative, with no detectable density in the shadow regions. The Sabatier exposure should then be increased just to the point at which the shadow regions end up satisfactorily dark. If the Sabatier exposure is too great, the highlights will be degraded.

Remember that if the film is overexposed, highlight zones will come out black. In fact, for this reason, if you use a high contrast film without a supplementary exposure, you will be restricted to scenes of moderate or low contrast. In such cases, if you try to photograph extremely high- contrast scenes, either the brightest highlights will be rendered black or much of the shadow areas will be black or dark grey, with little separation of tonal values.

Possible Applications. -

Making direct positives by the Sabatier method is not likely to be frequently practiced either by amateur or professional photographers. For only occasional applications of the method, it probably isn't worth the effort required to determine the optimum times for the supplementary and Sabatier exposures.

However, the method should find application where large numbers of transparencies are required on a routine basis. Once a setup is made ready for the development and exposures, the procedure is easily carried out and has the distinct advantage over traditional reversal processes of requiring only three processing solutions including the stop bath. The fact that no bleach solution (with the attendant environmental impact problem) is used is a factor in favor of the Sabatier method.

Also, it should be remembered that, with modification of the method, the fraction of the tonal range represented as a normal negative can be increased. That is, the method can be used in a more traditional way to prepare solarized negatives that yield prints with normal highlights and reversed shadows. The changes required to obtain such negatives are (1) reduction of the exposure index by a factor of 1/4 or 1/8 (generally corresponding to use of the film manufacturer's recommended exposure index) and (2) dilution of the developer by about a factor of 2 (corresponding to concentrations one- half of those listed in Table 4.5).

Sabatier Latensification

Figure 4.17 shows two Sabatier H & D curves, corresponding to strong and weak Sabatier exposures. When the Sabatier exposure is strong, the optical density in the film or paper approaches a high value on going to very low initial exposure values. However, when the Sabatier exposure is lowered somewhat, the density first rises and then falls on going to very low initial exposure values. Thus the H & D curve acquires a definite maximum, and one finds three distinct zones in the plot: a zone of positive slope corresponding to extremely low exposures, a zone of negative slope corresponding to moderately low exposures, and a zone of positive slope corresponding to ordinary exposure values. In a print made from a normal negative, the positive slope zones correspond to positive images as in the original scene; the negative slope zones correspond to negative images (reversal).

Fig. 4.17. Sabatier H & D curves. A. Weak second exposure. B. Strong second exposure.

To rationalize these curves, let us consider what would happen after the Sabatier exposure if there were no desensitization of any of the silver halide grains - that is, if the Sabatier effect did not exist.136 In such a case the Sabatier exposure would simply add on to the initial exposure, and continued development would cause the final H & D curve to look something like one of the solid curves in Figure 4.18, the position of the curve depending on the magnitude of the Sabatier exposure.*

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

* These curves are reasonable approximations, constructed while ignoring any "post- exposure light latensification"99 caused by the second exposure. Because the horizontal axis has a logarithmic scale, the curves for the uniform Sabatier exposures are not moved the same distance to the left of the "no Sabatier exposure" curve for all density values.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Fig. 4.18. The lowest solid curve (on the right side of the graph) is an H and D curve corresponding to a single initial range of exposures and normal development. Curves A and B are hypothetical curves corresponding to the same initial exposures, but with a subsequent uniform second exposure added on. (The second uniform exposure is weaker in A than in B.) The dashed curves show how curves A and B would be if Sabatier desensitization occurred before the second uniform exposure.

In reality, the silver halide grains that almost received enough first exposure to be developed in the first development are desensitized toward the Sabatier exposure. The fraction of the undeveloped grains that are desensitized increases with the magnitude of the initial exposure, causing the final H & D curves to follow the dashed curves in Figure 4.18, just like the curves in Figure 4.17.

Consider print solarization. If the very dark regions of the negative (corresponding to the print highlights) are completely featureless and of uniform density, then the density introduced in the highlight regions by the diffuse Sabatier exposure (either weak or strong) is also featureless and uniform. On the other hand, if there are density variations or images in the dark regions of the negative, it makes a difference whether the Sabatier exposure is weak or strong. A strong Sabatier exposure again produces featureless density in the highlight regions because the corresponding H & D curve (curve B in Figure 4.17) is essentially flat in the low- exposure region. A weak second exposure (corresponding to a positive slope in the low- exposure region of curve A) produces a low- contrast positive image in the otherwise completely undeveloped highlight regions.

Weak solarization thus amounts to a kind of "Sabatier photolatensification" in which otherwise undevelopable images are developed.128 The process amounts to the conversion of latent subimages to latent images by the absorption of photons, but only in the extremely low exposure regions. An example of this development of "undevelopable" highlight images is shown in Figure 4.19B, which should be compared with the "straight" print in Figure 4.19A. Notice that the Sabatier latensification does not degrade the image that forms in the first development, as would be the case if the print were given the second exposure before the first development.

Fig. 4.19. A Venice street scene. (A). A straight print. (B). A weakly solarized print. Notice the upper parts of the buildings in the background in (B) that are undeveloped in (A). [c/r W. L. Jolly.]

For Sabatier latensification, use either Agfa Brovira glossy paper or BroviraSpeed paper, grade 4 or 5. The first and second development times should be about 50 and 60 seconds, respectively, for Agfa Brovira, and 40 seconds each for BroviraSpeed. As a starting point for experimentation, try a second exposure of 4 seconds to a 25- watt bulb 4 feet over the developing tray. If any density forms in regions of zero initial exposure (such as a white print border), the second exposure was too strong.

Multiple Printing

The density introduced to the highlight (extreme low- exposure) regions of a print by the Sabatier exposure and subsequent development increases with the magnitude of the Sabatier exposure, just as one might expect. Indeed, a plot of the "solarization density" vs. log(Sabatier exposure) looks much like an ordinary H & D curve, except that the slope of the straight- line portion is relatively low, corresponding to low contrast. Figure 4.20 shows plots of this type for three grades of enlarging paper, compared with ordinary H & D curves for these papers.

Fig. 4.20. The solid curves are normal H and D curves for three grades of paper. The dashed curves show the densities formed in initially unexposed paper as a function of the second (Sabatier) exposure.

Consider a print with highlight areas that are truly blank, i.e., without any evidence of image in either the print or the negative. When such a print is solarized with a diffuse light source (that is, when all parts of the highlight areas receive the same level of illumination in the Sabatier exposure), the highlight areas naturally end up with a featureless, uniform density. However, it is possible to introduce imagery into the highlight areas by using an enlarger to project a negative image onto the print as it lies in the developing tray. The second image then develops only in what would otherwise be the blank highlight areas of the print, with very little overlap of the first and second images. Thus, one can very easily make multiple- image prints that fool even the most sophisticated photographers.128

Fig. 4.21. Blasé passengers on the Staten Island ferry. A composite of two scenes produced by solarization with a projected image. [c/r W. L. Jolly.]

Fig. 4.22. A photograph of Stonehenge combined by solarization with a projected image of a nebula. [c/r W. L. Jolly.]

When you first try out this multiple printing method, you may encounter difficulty in obtaining high enough densities in the second image. The second exposure time should not be extended beyond about 15 seconds to avoid secondary Sabatier fogging. Therefore it is best to use only BroviraSpeed paper (faster than Brovira) and to use the enlarger lens wide open for the second exposure. Also, avoid dense negatives for the second exposure. Of course, two enlargers are required if two different images are combined. And of course the second enlarger must be prefocussed (for example, by projecting onto a white sheet of paper lying in an empty tray). Special marks should be made on the tray and on the easel under the second enlarger so that the tray can be readily positioned such that the second image is projected onto the desired part of the photographic paper.

Miscellaneous Applications of Solarization

POP Solarization. -

In this procedure, devised by Berry27 and rediscovered by Rees,199 one soaks high contrast paper in developer and then exposes it under the enlarger. The image develops during the exposure, similar to the way that images print out on printing- out paper, or POP. As development proceeds, the shadow areas become desensitized to further exposure. In effect, the shadows are dodged and the highlights burn in, thus automatically reducing the contrast. Sometimes partial reversal occurs, as in ordinary solarization, especially when the print is given a second exposure while under the enlarger.

Berry recommends the following procedure: Set the enlarger lens near its maximum opening so that the the first exposure is short and bright. Focus a contrasty negative onto a piece of white paper, using a sheet of glass as an easel. Soak a sheet of high- contrast enlarging paper (such as Agfa Brovira No. 5) in fresh developer (e.g., 1:2 Dektol) for at least one minute. Position the paper, emulsion side up, on the glass sheet and gently remove all of the developer from the surface with a paper towel. Try a first exposure of five seconds; then wait for at least 30 seconds. The image should be weak, but very contrasty. Then give a second exposure for about three times the first exposure time. Return the print to the developer for 20- 30 seconds and, finally, stop, fix, wash and dry as usual.

If the two exposures are adjusted suitably, image reversal occurs only in the midtones, giving very interesting results. The very dark zones do not reverse because of the Sabatier desensitization, and the very light highlights do not reverse because they receive very little exposure.

I recommend that, before trying Berry's method, you read the article by Rees. He recommends a metol- only developer containing benzotriazole. Probably a suitable hybrid of the Berry and Rees procedures would give very good results.

Flashprinting. -

"Flashing" or "preexposure" of prints is a well- known procedure for effectively reducing the contrast of paper.2,107 The method is used for adding gray tones or textural details to an area which contains such bright tones that texture does not show up, even with burning in. The method has the advantage of not degrading the maximum black and dark regions of a print.

Flashing is generally accomplished by giving the paper a weak diffuse exposure before, during or after the printing. The proper exposure must be lower than the weakest exposure which by itself produces a detectable fog, and is usually found by trial and error. Frazier,88 who calls the procedure "flashprinting," points out that the flashing exposure can even be made during the development, where, if it comes late enough, Sabatier reversal effects are observed. Obviously a wide range of subtle effects is possible by variation of the two exposures and the time at which the second exposure is made.

Polaroid Film. -

Nobody seems to have had much luck in solarizing modern color Polaroid films. However, some success has been had with 4×5 Type 55 positive/negative black- and- white emulsions.5 After the film packet has been pulled through the rollers to start development and development has proceeded for about 10 seconds, the protective envelope is pulled back without peeling apart the negative/positive sandwich, and the negative side is flashed with a small electronic flash gun. Then the envelope is closed for the rest of the development time. Only the negative is appreciably solarized by this method. It can be subsequently used to make a solarized print with black border lines, either by conventional darkroom work or by copying with another Type 55 P/N film packet. In view of the trial and error required to find the optimum point during the development procedure for making the Sabatier exposure, and the optimum light intensity, the method hardly seems worthwhile, except perhaps for demonstration purposes.

Davidhazy66 has shown that interesting solarized images can be obtained from the paper negatives that are ordinarily thrown away when Polaroid type 667 film is used. The reversal can be seen taking place if one quickly separates the positive from the negative in room light. The reversal continues under room light until eventually the image stabilizes upon drying. Inasmuch as white border lines form in the negative, prints made from the negative have black border lines. Along with the solarization, the process introduces a lot of grain, causing a pronounced textural quality in the images.


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Last Modified: 8/14/97