US874222A - Combination of line and screen photography. - Google Patents

Description

No. 874,222. PATENTBD DEC. 17, 1907.

E. MBRTENS. I

COMBINATION OF LINE AND SCREEN PHOTOGRAPHY.

ARPLIOATION FILED JULY 12,1906.

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Mmssses ATTORNEYS E. MERTENS.

PATENTED DEC. 17, 1907.

COMBINATION OF LINE AND SCREEN PHOTOGRAPHY.

APPLICATION FILED JULY 12,1906.

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I HI U f/ I I? mmsisgh I INVENTOR g l mv Mumps ATTORNEYS UNITED STATES PATENT OFFICE.

EDUARD MERTENS, OF GROSS-LICIITERFELDE, NEAR BERLIN, GERMANY.

COMBINATION OF LINE AND SCREEN PHOTOGRAPHY.

To all whom it may concern:

Be it known that I, EDUARD MERTENS, a subject of the King of Prussia, residing at and whose post-ollice address is Gross-Lichterfclde, near Berlin, 36 Jagerstrasse, Prussia, Germany, have invented certain new and useful Improvements in the Combination of Line and Screen Photography.

The object of this invention is to provide a process whereby one may produce on a single sensitized surface, combined whole tone and half tone imeges.

My invention is as follows :The object to be photographed is separately drawn, printed or otherwise re )resented on a ground colored black, red yel ow, or green, or a mixture of these colors, one representation being of the whole tones, another representation being of the half tones. These representations are photographed on the same sensitized surface successively in either order, the whole tone representation being obtained without and the hall tone with a screen interposed. Illustrating this process, suppose the object to be photographed consists of a drawing of flowers executed in black-gray-white half tones on a white ground, which is surrounded by a pen-drawing executed with black ink, or by printed text. First, a negative copy of the flowers o the model, in so far as it comprises half tones, is transferred to a black ground, and then the pen drawing is introduced in a light color, for instance, white or blue, on a second black sheet. The negative copy may consist, for example, of an inkdrawing, which in white or blue color consists of light values, which are the opposite of those which the photographic plate is to show. Therefore, in this drawing, that will appear white or blue which in the original or in the negative must be black, and that which is to be light gray in the negative, will here be dark gray or dark blue. The first copy is now photographed with the interposition of a screen. The objective is then. closed, and the second copy, '11. e. the line drawing is substituted, and this is now photographed on the same plate after the screen has lbeeln removed. In this malpner, on a sing e ate, a ositive photograp ic image is produdied in which the halt-tones are broken up by screen, while the whole-tones are not broken up. It is evident that while the back-ground of the object is light, or a light surrounds the picture, the background would be photographed and this would make it im- Specification oi Letters Patent.

Application filed July 12 Patented 11ecr1'7, 1907.

, 1906. Serial No. 325.940

possible to photograph. several copies one over the other. Unless the background is dark, red, yellow or green, or a mixture of these colors, the present form of the invention could not be carried out. The work may be facilitated by using transparent films for making the negatively drawn representations, the films being colored with the abovenamed non-actinic colors. The films may be translucent, but in such case, when the photograph is to be taken, they must be laid on a black ground, or one which is colored with the above-named non-actiriic colors. The latter method offers the advantage that models which are drawn black on white can. be traced in white or blue color onto the trans parent films, by means of register-crosses, which have previously been marked on the original drawing. Before hotographing, the various films are then astened, cross upon cross, upon the support and then, as the successive films are photographed, only one film after the other need be removed.

Instead of re-drawing the flower and pendrawing on a black ground, negative representations produced by mechanical means might also be used, which negatives are either photographed by permitting a light ground to shine through, or are illuminated at their transparent places. Here, too, light or transparent half-tone images, as well as line drawings, are photographed one after the other, on the same sensitized plate, each by itself, with a border non-transparent toned n ith a color chemically inactive during photographmg. 1

The process forming the basis of this application makes it possible also to break up individual portions of the flowers or of the leaves by diflerent screens, by taking not only two consecutive photographs on the same plate, as above described, but three or more photographs. For this purpose, for example, on photographing the one half-tone model a cross-screen is used; on photographing the second half-tone drawing, which for instance may form a part of the flower above referred to, a line screen, so that by changing the screens, or diaphragms, various screen structures may be effected beside each other. Whenmaking photogravure films for use on producing fabric printing rollers, the process permits the breaking up of the various parts of the design, according to need, into numerous lineations b inserting various hatching screens, and at t e same time combining the outlines and line drawings with the hatching.

lines, by successive photographing, onto one plate or film.

In the above described process it is permissible, thou 11 not always advantageous, to take two w ole-tone and half-tone draw ings, mountedexactly one over the other, and belonging to the same design, ofwhich the under drawing is drawn on a dark ground, while the upper drawing must be drawn on a translucent film, and first to photograph these simultaneously, with the. interposition of a screen, and then to photograph the line drawing again, alone, without screen.

Instead of effecting the combination of screen image and whole-tone image on one plate by process of photographing, it may of course be done also by successive copies and interposition of thin screen films. But the first method w ill have to be employedin all cases, in which the reproduction is to be of different size from the original, and where an advantage may be obtained by breaking up the image by screen, objective and various diaphragms. These processes may also be successfully used for the so-called gigantography.

The photographic apparatus necessary for taking the photographs may differ from the photographic apparatus hitherto suited to half-tone photographing only in this that one of several screens, during the exposure or the interrupted exposures, can be easily inserted and taken out, or changed, as far as possible without opening the camera, and as far as possible in such manner that this change may be effected from the outside.

One form of the contrivances for inserting and taking out screens, suited to carrying out 4o the process, would for instance consist in this that in the interior of the photographic camera, or on the plate-holder, hinges are aflixed, to which the frames of the screens are fastened in such manner that the same may be opened, door-like, into the camera, that is toward the objective, so that, on taking out, one or several screens come to lie against the side of the camera or the bellows, giving a free field of sight while during a screen-exposure the screen in uestion is set parallel to the plate. So, also, t e inserting and taking out could be effected from the outside in such a way that the screens or their frames are slid into the camera or plate-holder, and drawn out, from one or several slides, in the same manner as the slide of a plate-holder.

The process is illustrated in simple form in the accompanying drawings in which Figure 1 shows the full tones of a clover leaf; Fig. 2 shows the half tone portions of the leaf; Fig. 2, shows the ima e resulting on the negative after exposure or the half tones; Fig. 3 shows the two images shown in Figs. 1 and 2 arran ed before the camera; Fig. 4 shows the comp eted icture upon the sensitive film; Figs. 5, 6 an 7 show the different petals of the leaf separately drawn to secure the different half-tones shown in Fig 8; Fig. 9 shows these separate sheets arranged before the camera for photography; and Fig. 10 is a cross section of a camera showing an arrangement of the line screens within the same.

It will be seen in Figs. 1 to 4 that the full tone image a is arranged behind the half tone image b so that upon the first exposure of the film through the screen the image b, Fig. 2" is produced. Upon removing the screen and the half tone image from in front of the camera and again exposing the film, the full tone image a, which has been arranged at the start in exact coincidence with the half tone image b by means of the cross marks shown, is received by the film, with theresult that the completed image in Fig. 4 is secured.

In Figs. 5 to 9 is represented themethod of procedure where dlfi'erent tones for the different petals of the leaf are attained by exposure through different screens respectively.

The hinging of the screens f, g and h at f, g and h within the camera is shown in Fig. 10.

claim as my invention:

1. The herein described process of producing photographic images, consisting in producing whole-tones and half-tones, first one and then the other, on the same sensi tized surface.

2. The herein described process of producing photographic images, consisting in successively exposing to the same sensitized surface whole-tone and half-tone images on grounds of non-actinic color.

3. The herein described process of pro ducing photographic images, consisting in producing successively on a single sensitlzed surface whole and half-tone photo aphic images from images on transparent ms of non-actinic color.

In testimony whereof I have signed my name to this specification, in the presence of two subscribing witnesses.

EDUARD MERTENS.

Witnesses:

JEAN GRUND, CARL GRUND.

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