DE1063458B - Process for the production of tone-corrected copies - Google Patents

Description

GERMAN

Photographic methods for tonal value correction are already known. They usually get like that carried out that a "normal tonal value" recording, which contains certain tonal value errors, with a second Recording or copy of the same template (mask) is copied in register. The copy of the combination Both recordings then represent a tone-corrected image. For emphasizing the light drawing A highlight or depth mask is produced in the negative or the depth drawing in the positive, which forms an underexposed picture containing only the brightest highlights or deepest shadows. This is usually done on less sensitive photographic material or with a shorter exposure time made as the normal tonal recording.

The two light-sensitive layers for the normal tone value and the tone value extract can also be arranged on the same support ((»halftone layer« and »mask layer«), with their spectral Sensitivity can be either in the same or in different ranges. In the latter case It is also possible to combine the two layers into a single layer, which is the highest density - the highlights - of a negative a blackening curve that rises more steeply than in the semitones and depths having.

However, materials of this known type - used as negative recording material - only lead to improved highlighting, while the shading is still insufficient.

It has now been found that this deficiency can be overcome if one looks for inclusion a (per se known) light-sensitive material with one or more layers used, which in the higher densities show a steeper gradation than in the lower densities, which is a substantial one show uniform gradation, but this material according to the invention to a dye image or combined dye silver image processed, which actinic light of different wavelengths strongly absorbed and thus in the subsequent copying process depending on the spectral composition of the copying light used results in different steep gradations, whereupon this Dye image with two types of light at the same time or one behind the other on one for both types of light different sensitive material is copied in such a way that with one kind of actinic Light an image of the original corrected with regard to the depth drawing and with the other type of actinic Light a correction of the light drawing is achieved so that a regarding the depths and Light drawing corrected image results.

It is from US Pat. No. 2,737,457

Method of manufacture
of tone-corrected copies

Applicant:
Agfa Aktiengesellschaft,
Leverkusen-Bayerwerk,
Kaiser-Wilhelm-Allee

Dr. Erhard Hellmig, Leverkusen,
has been named as the inventor

already known, for the purpose of tonal value correction on a normal negative layer next to one Silver image to develop a dye image and the combined image with different ones if necessary To copy types of light, however, the copy is not made consecutively on the same material. Through this but only the general steepness of the finished negative is influenced over the entire gray tones, however, tonal value correction according to the present method is not achieved. Will continue in the known, in contrast to the registered process, a standard positive material is used as the copying material used. Another difference is that according to the invention a special recording material is used while the known method is carried out with normal negative and positive material. According to the invention, therefore a real masking, d. H. a better sound separation, achieved because the mask of the copy material, so the steep layer responds to the more strongly absorbed type of light, i.e. to the steep negative, with a double Effect is caused.

The method is explained in more detail below, wherein the photographic recording material which both a two-layer material with a halftone and mask layer and a single-layer material with a corresponding one may be sensitometric properties, for example a yellow coupling color component contains.

After exposure, color development and fixation in a neutral fixer, a silver image is obtained, combined with a yellow dye image. Amount of silver and color components of the photosensitive Materials are coordinated in such a way that the combined image, viewed through a green filter, shows the tone value gradient as with the well-known black and white light mask film, so also the increased light drawing shows. When exposed to green light,

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1

there is a light-masked one, and an additional depth-masked one in the case of post-exposure with blue radiation Image as it corresponds to the course of the known person curve. When using blue-green With copier light, this result can be achieved with a single exposure. Particularly effective becomes the depth drawing, if the copy material exists as a halftone and mask layer Is two-layer material on which the mask layer is one to the negative's image dye complementary, i.e. in the present example a sensitivity lying in the blue-violet part of the spectrum has, while the halftone layer in a broader spectral region z. B. orthochromatic or is sensitive to light throughout the rest of the spectrum.

In the drawing, the method is explained on the basis of schematized sensitometer curves for the example described. _v

In Fig. 1 a, the curve of the negative image, measured through a green filter, is reproduced; she shows those for the known, z. B. commercial black and white developed specialty photographic materials characteristic shape with increased light differentiation. The curve behind a strict blue filter Fig. 1b shows; because the negative image in the present example is colored yellow, i.e. strong blue light absorbed, it now has a significantly steeper gradation than in Fig. 1 a.

Now take the negative with green light on an appropriately light-sensitive material copied, the result is a copy corrected only in the highlights with the one drawn in Fig. 2 a Blackening progression. This is done afterwards using the same negative on the same copy material an exposure with blue rays, so copy because of the steepness of the negative gradation (Fig. 1 b) only the areas of highest transparency in the negative. Those are the lows, and in the copy occurs in addition to the light masking, an emphasis on the depth drawing. The result is that shown in Fig. 2b The sensitometer curve shown, which in addition to the highlights, the depth masking achieved at the upper end of the The blackening curve clearly shows that it represents the well-known "ideal" sound separation curve for each person.

The invention is not restricted to the example just described. The procedure is concerning the spectral sensitivity of the recording material, its processing, the color and the type of Coloring capable of the most varied changes. In particular, the material can be panchromatic Possess awareness; it is therefore suitable as a color separation material in multicolor reproduction. The image can also be used instead of a combined dye-silver image as in the example above A pure dye image can be processed, which is the case with color generation by chromogenic development can be achieved in a known manner by bleaching and fixing (or by bleach-fixing). Should the image have the same technical copy effect as the combined dye silver image in above example, the recording must have a yellow-orange tone, the copying material being orthochromatic Material, if necessary with a blue-sensitive mask layer, must be. The procedure according to the invention can also be carried out with two-layer materials according to patent application A 22305 IVa / 57d of March 19, 1955 and A 23614 IVa / 27d of October 20, 1955, in which the mask layer is one of the halftone layer has a different color and is counter-458

possibly made of pure silver or of a dye silver image.

Incidentally, the tone of the dye or dye silver image is not subject to any restrictions; besides yellow or yellow-orange z. B. also be purple, blue-green, red, blue-violet, green. It goes without saying that the spectral sensitivity of the copy material must match the color of the negative be adjusted; it must be at least in the most absorbent of the dye image and be sensitive in a further lower absorbing spectral range. Has practical significance z. B. the case of a purple dye-silver picture, where - in reverse as in the example above - the light-corrected copy with blue, but the depth mask with green or yellow rays on orthochromatic Material must be copied. In the event that the copy material is a halftone and a mask layer is two-layer material, the halftone layer must be sensitive to blue, the mask layer be orthochromatically sensitized or sensitive to green.

In practice, it is very generally the case that the same light-sensitive material is used for the copy Material is used in the same way as for the recording, but the copy is in contrast to the recording is to be treated as usual in a non-coupling (black and white) developer. Provides the recording and copying material is a two-layer material consisting of halftone and mask layers according to what has been said above, the correct assignment of the image color of the negative image and Pay attention to the spectral sensitivity of the halftone and mask layers of the copy material.

The type of coloring, which itself is not the subject of the invention, can be carried out by any desired method to be made; it can be used both during processing, in particular simultaneously with the Development, either together with a processing sub-process or between two of these Sub-processes take place or can also be carried out after processing. Besides the procedure In chromogenic development, a known possible coloring process is the toning of the silver image z. B. by means of lead or uranium toners (see Eder, Rezepte and Tables, 1948, p. 171), the silver bleaching process, the washing process, the pickling process, called the color transfer process. Also the use of known non-coupling developers whose Oxidation products give an additional colored picture, such as B. pyrogallol, catechol, chlorohydroquinone, results in a combined dye / silver image which can be used in accordance with the invention can.

As an example of the creation of the dye image after the black and white processing of the Lichtern corrected recording is their production by copying the negative recording on a transparent one Diazo film mentioned, which then in a known manner, for. B. in ammonia gas, to a FarbStofFbild is being developed. The fitting combination of the dye image with the original image results the combined dye silver image according to the invention, of which then according to the method described Tone-corrected copy is to be made in highlights and shadows.

example 1

One of the well-known halogen silver gelatine emulsions is attached to a transparent carrier made of acetyl cellulose.

Claims (6)

sions cast, which shows a rise twice as steep in the blackenings above 1.5 as in the lower blackenings. The emulsion is sensitized to green in a known manner and contains one of the known colorless, yellow-coupling color components for chromogenic development. There is a hardened gelatin layer above (to protect the light-sensitive layer against mechanical damage). After exposure, using a black and white image as a template, the film is treated with one of the known color developers for 5 minutes, then watered for 1 minute and then placed in a neutral fixer for 10 minutes, watered for 10 minutes and dried. The finished image contains an image made up of silver and yellow dye. The choice of emulsion was made in such a way that the finished image, measured behind a strict green filter (e.g. Agfa filter No. 54), shows a gradation of 1.0, above the blackness of 1.5 a gradation of 2.0. The amount of components was measured so that the gradation behind a strict blue filter (e.g. Agfa filter No. 552) is 3.0. The negative image is now taken with green light from the wavelength range 500 to 600 ιημ (ζ. Β. With Agfa filter no. 54), then with blue light from the wavelength range 400 to 500 ιημ (ζ. Β. With Agfa filter no . 552) is copied onto a black and white developed two-layer material, which consists of an orthochromatic halftone layer with a gradation of 1.3 and an overlying, only blue-sensitive layer with a gradation of 1.5 and a sensitivity 40 times as low as the orthochromatic layer. The exposure to blue rays is measured in such a way that only the areas of the image that are covered in black (the shadow areas) are copied. The copy is then processed in a known manner in a black and white developer (Metol-Hydroquinone) for 6 minutes, watered, fixed, watered again and dried. Example 2 Structure of the recording material as in Example 1, the photosensitive layer containing a yellow-orange coupling component instead of the yellow component or a purple component in addition to the yellow component and the green absorption being of the same size as the absorption of the pure silver image of the recording layer in the above case The material is processed into a pure dye image, which is known to take place by bleaching and fixing the image silver after color development. The copying process is carried out in the same way as in Example 1. Example 3 One on commercially available material, e.g. Agfa -LM film, made black and white negative image automatically masked in the lights, is copied with arc light onto one of the commercially available diazo foils with arc light, which is then developed in ammonia to an intensely yellow negative image. The processed diazo foil is combined with the black and white negative in register iert and then serves as a master copy for the production of the slide; the procedure is continued as in Example 1. Example 4 A black-and-white photograph made on the material described in Example 1 is treated after developing and fixing in one of the known uranium toners (see Eder, Rezepte und Tables, Halle 1948, 20th to 22nd edition, p. 171). 500 g of yellow blood liquor salt is dissolved in 10 l of water, to this one add 50 cm3 of a 1% strength potassium dichromate solution. The whole is added to a solution of g uranium nitrate, 500 g oxalic acid, 40 liters of water. The black and white photograph is bathed in the mixed solution for 5 minutes and then watered. The toned image is copied as above. Patent claims: 1. A method for the production of tone-corrected copies, characterized in that one for recording a (known per se) photographic material with one or more light-sensitive layers are used, which have a steeper gradation in the heavier blacks has than in the weaker, but that according to the invention in one or more Layers either a pure dye image or a combined dye and silver image and this (s) image (s) with types of light from different spectral ranges simultaneously or one after the other copied onto a photosensitive material, the spectral sensitivity of which corresponds to the image color of the Negatives are matched so that they are most absorbed by the dye image and one further, more weakly absorbed spectral range extends. 2. The method according to claim 1, characterized in that one photosensitive for the copy Material used that absorbed more strongly from the dye or dye silver image Type of light responds more steeply than to the type of light that is less strongly absorbed by this picture. 3. The method according to claim 1 or 2, characterized in that for recording and copying the same photosensitive material is used and the recording is made with a coupling, however, the copy is treated with a non-coupling developer. 4. The method according to claim 1, characterized in that the recording material has a yellow coupler or contains a magenta coupler and that the exposed picture forms a dye overlay is processed. 5. The method according to claim 1, characterized in that the recording material is an orange coupler contains and that the exposed image is processed into a pure dye image. 6. The method according to claim 1, 2 and 4, characterized in that the dye image in a particular Layer - on a special support or together with that in need of correction in the depths Image · - is generated. Considered publications:
U.S. Patent No. 2,737,457. 1 sheet of drawings ® 909 607/345 S.