US2356439A - Method of making fade-outs by aftertreatment - Google Patents

Description

Patented Aug. 22, 1944 METHOD or MAKING FADE-OUTS BY AFTERTREATMENT Paul S. Aexand Charles H. Guell, Rochester, N. Y.,

assignors to Eastman Kodak Company, Rochester, N. Y., a corporation of New Jersey No Drawing. Application February 11, 1943, Serial No. 475,506

4 Claims.

The invention herein describes methods of making fade-ins and fade-outs and iris-ins? and iris-outs? upon motion-picture films. These are herein referred to generically as fades? and irises. The methods herein described are of particular utility with films containing multi' colorimages.

When pictures are made in color, the resultant images are usually composed of dye or of colored com-pounds resulting from the photographic process by which they are made.

In the camera, fade-outs are made by decreasingcontinuously and uniformly over the picture area the light reaching the film through the optical system and is introduced as the end of the scene is approached. Thus, as the fade-out progressed, the negative is more and more under-. exposed until at the end of the scene no image whatever is produced. The reverse is true in a fade-in, when the. exposure is gradually increased.

When a print is made from a negative which contains a fade-out, the printing exposure remains constant, so that the frames are progressively more dense and deficient in contrast. The fading consists of the disappearance of, successively, the shadow detail, the medium tones, and finally the highlights.

As the art of editing developed, it became neeessary to make the fades in the developed negative after the cutting. This was sometimes accomplished by varying the printing exposure, an operation that must be repeated with every printing and requiring such careful attention as to be impractical commercially. It was also produced by controlled chemical treatments with photographic reducing solution. Another method is to apply dye solutions producing a dye wedge the length and character of which is determined by the requirements of the particular scene.

Another method has been to laminate upon the developed film a sensitive layer which is then exposed and developed to produce the desired fade or iris, or to laminate on the finished film a previously exposed and developed layer containing the developed fade or iris. An example of this last is shown in U. S. Patent Favour 1,817,977, granted August 11, 1931.

All of these methods have certain disadvantages, particularly when used with color film of the type containing multi-layer, color-component dye images. Those which depend on preformed images are incapable of control and the desired effect or central iris point may not be producible with the selection of preformed strips obtainable.

Color films having several color component layers are already somewhat thicker than'blackand-white film carrying a single emulsion layer, 7 and the addition of another layer by coating or give false color rendering; and the application of a dye must be done by hand and must also be appropriate to the particular colors of the scene which may be changing. The transmissionchan acteristios of the dye'are also not always uniform; as for instance it may be greenish in the highlights, and red in the maximum densities.

The lpresent invention relates to a method of producing in film containing color images fades and irises by the production in the emulsion layer or layers of a metallic silver fade or iris image.- This method avoids the objections noted above. In brief, this method consists of forming or depositing within the emulsion a dispersion of sil-, ver which is uniform over the area, although it is possible that it may vary in the depth of the emulsion, and exposing this to a controlled exposure of the desired fade or iris and then developing a silver image of the desired fade or iris which may be shortened or protracted as desired, or the iris may be of any desired shape or position in the frame.

An example of a way in which the process may be carried out will now be given: The film, usually containing the color component dye images inseveral layers but containing no silver or silver salt, is bathed in 5 per cent silver nitrate solution in water for two minutes. After any solution remaining on the surface is squeegeed off, the film is immersed in a 10 per cent solution of potassium bromide in water for another one sired step or iris exposure and developed; or it may be given a uniform fog exposure andcontrolled development to yield the desired wedge. In the latter case it may be examined by a safe light. We have found, however, that exposure to ultraviolet results in a very even and satis-- factory fade.

lamp at a distance of one foot for about a minute for a full exposure.

Development may be in any usual developer,

such as an MQ developer, one being the following:

Methyl paramidophenol sulfate grams 2.0 Sodium sulfite, desiccated do 100.0 Hydroquinone do 5.0 Borax, granular do 2.0 Water, to make liters 1.0

The silver wedges thus produced are very uniform, and there is no change in color value from the dye picture to the area where the wedge begins. The wedge is quite neutral throughout the entire range of density; but if a bluer image is desired, blue-black toning agents such as rhodanine and thiobarbaturic acid may be used to produce bluer images.

If a colored wedge is desired, development may be with a coupler developer to produce the desired color.

It is to be understood that, While particularly described and the advantages pointed out in connection with one type of color film, the method with which it has particular advantages alsohas advantages and can ,be used with films of all types containing -black-and-white or color images.

We therefore recommend such alight as is produced by a 100-watt mercury vapor Having thus described our invention, what we claim is:

1. A method of obtaining graduated images in motion-picture film previously containing completedphotographic images that comprises depositing sensitive silver salts uniformly within the image-containing layer, exposing the film to a, graduated exposure to form a wedge or iris, and developing an image from said exposure, and removing any unexposed silver salts.

2. A method of obtaining graduated images in motion-picture film previously containing completedphotographic images that comprises depositing sensitive silver salts uniformly within the image-containing layer, exposing the film to a graduated wedge exposure, and developing a graduated silver wedge image in the layer and removing the unexposed silver salts.

3. A method of obtaining graduated images in a motion-picture film containing photographic images in a gelatin layer that comprises bathing the film first in a silver nitrate solution and then in an alkali-halide solution, thus obtaining silver halide salts in the gelatin layer, exposing the film to a light image graduated lengthwise of the film, developing a silver image in the film and removing the residual silver salts.

4. A method of obtaining graduated images in a motion-picture film containing color component dye images in gelatin layers that comprises bathing the film first in a silver nitrate solution, then in an alkali-halide solution, thus obtaining silver halide salts in the gelatin layers, exposing the filmto a light image graduated lengthwiseof