DE974412C - Process for the production of color-enhanced copies, duplicate images or reproductions of multicolored transparent or reflective originals without or using negative or positive intermediate color images - Google Patents

Description

ISSUED DECEMBER 15, 1960

A 33354 IVa / 57b

Intermediate color images

Any multicolor reproduction, regardless of the process by which it is carried out (photographic Multicolor copying processes, e.g. B. via multi-layer color film, reproduction via color separations), is known to cause color distortions, in particular loss of color saturation and color accuracy with himself. These losses occur even in the simplest photographic reproduction process "with only one copy process, such as the so-called color negative-positive process clearly visible through multilayer material; the more color copying passes, the stronger they become are required to produce the final reproduction. That is why the said Loss of color value in the production of duplicates is particularly large; equally great loss of color occur in the production of color reproductions from multicolor originals when they are over several intermediate recordings are made on multicolor film; z. B. if a supervisory authority

009 661/2

nal first on a multi-layer color film in natural Colors (color slide) is recorded, which is then copied onto a color negative film from which the color separations required for the reproduction are then made.

The mentioned color losses are due to the optical defects of the dyes all in the reproduction process involved images their cause. In particular, the purple image dye ίο always has too little permeability or remission for blue light, which it should completely transmit or remit; the consequence of this is that the yellow sub-image of the multicolor image in question is gradation-wise compared to the other colored ones Partial images is disadvantaged. This deficiency in a picture is now intensified with every further color copying or reproduction process, so that the yellow partial image disappears more and more with each reproduction step. ao To counter this deficiency, it is already known to use the contrast of the yellow partial image of to be kept steeper from the start than the contrast of the purple and blue-green partial image. So was recommended after a known method of making duplicates, the contrast of the yellow sub-image in the multi-color original image beyond the extent necessary for visual observation addition to increase. Another method is used to produce color-enhanced copies from a multilayer negative the same dimensional. would be suggested for the color negative image. In In both cases, a special photographic material with excessive yellowness is required; the known method is therefore not "normal" with the usual visual or sensitometric to carry out coordinated color materials. But if the contrast of the yellow image is after Completion of the multicolor original increased by additionally applied means, for example by uncovering a yellow-colored one drawn from the color image with a blue-violet filter If the gradation is the same as the gradation of the original image, further difficulties arise on: The mask that was drawn with the blue-violet filter is used of the unwanted absorptions of the purple and. blue-green partial image Color separation errors also transferred, so that in addition to the intended purpose of increasing the yellow gradation but an enlargement of the chromatic aberration goes hand in hand. There are also multicolor pictures, especially color slides that already have such a high contrast range that the further subdivision of the yellow image by a separate yellow mask to practical difficulties in the further reproduction process, in particular with regard to the reproduction of the tonal values in the Duplicate, so that this route is not feasible in all cases.

It has now been found that these disadvantages can be avoided if, from the original image, that can be a see-through or a top-view image, with a green filter a gradation-based one Opposite mask in purple color and with a red filter an equally gradation-wise one Mask in blue-green color is drawn, which then both at the same time and contour-covering with can be combined with the original image. The gradations of the two masks can be different to get voted; but preferably they are the same. These two masks are now effective Gradation-lowering on the purple or blue-green layer of the original image and thus relatively increasing the gradation on the yellow partial image of the original image; but they also have an effect color-correcting on the yellow part of the picture, since it has the " originally present unwanted absorptions of the purple and blue-green partial image of the original because of the blue absorption of the mask dyes. This color correcting Effect can be increased if the mask dyes are chosen so that their Density in the blue copy light is higher than the corresponding density of the purple and / or des blue-green dye of the multicolor original, if in other words the purple color one mask tends towards red, the blue-green color of the other mask tends towards green. Another Color improvement occurs when the green absorption of the blue-green mask also increases, in the same. But the green absorption of the red mask is reduced :, d. H. if the color for the originally purple mask is even more yellow (orange), but blacker for the blue-green mask is chosen.

The figures show the gradation relationships graphically:

Fig. 1 a and 2 a for the gradations of the purple and blue-green mask, measured in blue, green and red light. Fig. Ib and 2 b represent, derived therefrom, the spectral transmission functions of the image dyes of the both masks. They were drawn in such a way that the numerical values of the table or the ordinate values of the gradation curves (Fig. 1 a and 2 a) in the middle of the respective third of the spectrum are (i.e. at 450, 550 and 650 ηιμ, filter or. .Sensitization focus of the photosensitive Mask layer.

For the production of the colored masks is no basically any color process suitable, especially chromogenic development, the silver color bleaching process, the pickling process, the Pinatypie or the suction processi.

The mentioned masks can be used both in separate and in inseparable form will; in the latter case, preferably as a two-layer photographic material on a common Carrier, one of the layers for green., The other of the layers for red Sensitive to light. In order to eliminate the natural sensitivity to blue, both Layers can be attached in a known manner to a decolorizable yellow filter. Appropriately included the emulsion layers' one accordingly colored color couplers (or a mixture of such

Coupler), so that the color formation is carried out by chromogenic development of this material can be.

Basically the same effect, if not as perfect as two separately sensitized mask layers also exert a single one with green and red (= yellow) light Single-layer material successively or simultaneously exposed mask from which in the mixed color from the two mask colors (purple and blue-green), i.e. blue-violet, is colored. This too Material can be made insensitive to blue light by known means (yellow filter, yellow Layer coloring, chlorobromide silver emulsion, etc.), so that it is also exposed to unfiltered light can be.

The mask according to the invention is now in a known manner with the multicolor image of the it was drawn, united in register; this can be done in contact as well as in Strählegange, in the latter case preferably if the mask has a different format than the Template or if the mask is from an original template (reflective image or colored spatial Object) was drawn. In principle, the mask according to the invention can be used by anyone within a multi-stage reproduction process used 'color images drawn and with this the same images can be combined, but expediently from one at the beginning of the reproduction process standing color images so that the yellow gradation is retained from the start. Of course is also a repeated application of masking within the same reproduction process possible. Such a masked color image can also be used as a master copy for the Production of a color copy or a duplicate or also serve as a reproduction template.

Of course, the process can be carried out in the same way if the photographic Multicolor image not the usual, so-called natural association of sensitization and Has image color.

Claims (9)

Patent claims: i. Process for the production of color-enhanced Copies, duplicates or reproductions of multicolored transparent or reflective originals with or without use of negative or positive intermediate color images, characterized in that the Original and / or at least one of the intermediate color images with a purple and the blue-green partial image can be provided with a gradation-reducing mask. 2. The method according to claim i, characterized in that that the first intermediate color image in the sequence of the reproduction steps is provided with the mask mentioned in claim ι. 3. The method according to claim ι and 2, characterized in that the color of at least one of the two color masks is the same as the color of the corresponding partial image of the masked color image is. 4. The method according to claim 1 and 2, characterized characterized in that the color is at least one, preferably the purple. Company rbmaske a has higher gradation in the blue spectral region than the color of the corresponding partial image of the multicolor original. 5. The method according to claim 1 to 3, characterized in that the color of the blue-green Mask has a higher green absorption than the color of the corresponding partial image of the multicolor original Has. 6. The method according to claim 4, characterized in that that the sum of the gradations of the two masks in the green light is equal to the Is the sum of the gradations in the red light. 7. The method according to claim 1 to.5, characterized characterized in that the two masks are arranged on a common carrier. 8. The method according to claim 1 to 7, characterized in that the mask is produced by exposing a single-layer material to green and red actinic light simultaneously or sequentially and then coloring the mask in the mixed color of the individual masks. 9. The method according to claim 1 to 7, characterized in that the colored masks by chromogenic development can be generated. Considered publications:
Journal "Photographische Korrespondenz", 1955. P. 57, 1954, P. 19 to 23;
German Patent No. 742 132;
British Patent No. 553 229. 1 sheet of drawings © 609 © 9 / 43S 10.56 (009 661/2 12.60)