US1092545A - Process of printing from photographic negatives. - Google Patents

Description

J1 H, SNAPP. PROGBSS o? PRINUNG PROM PHOTOGRAPH-1G NEGMNBS.

I APPLICATION FILED MA1/31, 19l2.

atented Apr. 7, 191@ LOQQ.

fw @E j@ C@ .and

JOHN H. snare, or WASHINGTON, nrs'rnrc'r orcoronare..

PRGCESS Gl? PRINTNC-t FROM PHOTOGRAPI-IIC NEGATIVES.

Specification of Letters Patent.

latente d Apr. t', 19M

Application filed May B1, 1912. Serial No. 700,786.

To NZZ 'savio/n, 13' may concern.'

lie it known that I, JOHN H. SrL-irma citizen et the United States, residing at 4516 M street, northwest, lVashington, in the District olf Columbia, have invented certain new and t ful Improvements in Processes ot Printing from Photographie Negatives, of which :he following is a specification.

My invention relates to the art of photogpraphy and more particularly to a method of reducing in the photographic print the contrasts between the high lights adows as they appear in the negative.

lt 1s well known that the ordinary photographic negative does not' properly represent objects asthey appear to the eye because ot the strong Icontrasts between the high lights and the shadows and also due to the i'act that unnatural contrasts are produced because ot the dilierent actinie properties ot' the objects due to their colors. For these reasons the positive printed troni a negative exaggeratescertain features of the object and minimizes others, causing an unnatural and Oft-times unpleasant ettect. 'Various expediente have been resorted to for the purpose of overcoming or eliminating these detect-s and usually by some form oit retcuching or other treatment ot the negative itself.

The purpose ot' my invention is to provide a method of printing from the untouched negative and eliminating or counteracting the improper or undesirable contrasts or shadows and causing the diiterent portions of the picture to print in their proper or desired density and tone. By my method I am also enabled to reduce to any desired amount the printing of any particular portion of the picture. l

My invention will be clearly understood from the following description in connection with the accompanying drawings in Which- Figure l, is a perspective View of an apparatus for carrying out my method of pho-l tographic printing; Fig. 2, is a cross-section on the line Q-Q of Fig. l; Fig. 3, is a rear perspective view of a portion of the iilm-carrier shown in Fig; l; Fig. 4, is a top plan view of a. printing frame inclosing a positive print; and Fig. 5 is a plan View oila negative corresponding with the posiftivein Figs.

Inlhgs. l and 2, I have shown an apparatus adapted to be used in carrying out my method of printing, in which is an ordinary printing frame, lmving the usual sectional back-hoard hinged together at 3, and holding the printing paper et, iirmly pressed against the negative 5 by means of the leal" springs (3, pivotally mounted to swing upon pivot screws 7, and adaptedy to lock at their ends in the grooves 8, in the sides of the frame.

My method of counteracting or eliminating the effect of the undesirable parts ot the negative and of reducing' the shadowsor properly proportioning their density rela-- tive to the high lights of the picture, involves the interposition oi a translucent film. carrying a reducing medium between the negative and the source of light by `which the print-ing or exposure is ciiected and out of Contact with the negative' so that no sharp lines of demarcation shall be produced.

A suitable film for support-ing the translucent reducing mediuiu may be formed of tissue paper or tracing linen represented at 10, and secured to a `carrying frame 12, which is made to tit over the printing-frame l. When the parts are in position, the ilm 10, will be spaced or separated from the negative 5, by a space equal to the width of the bevel or rabbet let of the printing-frame and the thickness of the carrying-:trame l2, and this permits the dispersion of the light between the film and the negative and prevents any sharp lines being produced upon the positive by the reducing medium. There is, therefore, no danger ot sudden contrasts` due to the use ci the reducing medium and it is unnecessary to move the parts during printing as in the use of shields in the dodging or shadowing operation employed by photographers to restralin the, printing from portions of a negative.`

I have discovered that an opaque 'substance will not serve the purpose of a reducing medium but that the medium must be translucent or semi-translucent and moreover it should be capable of adhering to the silipporting ilm and of being distributed accurately in order to graduate its density; I have discovered that amorphous powdered carbon when combined with an adhesive vehicle which may be resinous, saponaceous, waxen or a combination thereof, is suitable for producing tho reducing medium in my method of printing.

For the purposes of illustration, I have shown in Fig. 5 a negative of a portrait. lf

ilo

I the positive isprinted in the usual manner from this negative the effect will be very displeasing by reason of the contrasts be# tween high lights and shadows and the exaggerations produced. Thus, for example,

the fleshy portions of the face just' under the eyes produce shadows,*appearing inthe negative as curved transparent lines, as at 15.

'.Again certain-parts of the hair are practicallytransparent and will produce in the positive dense parts which will show no detail. The saine is true' of certain portions of the clothing. According tomy method,

theseparts may be4 restrained in the printing operation by interposing a translucent medium' .having a, density proportional to thedegree of transparency of these parts of the negative. Thus in Fig. 1 I have indicated at 15, thin bands of the reducing vmedium yplaced upon the supporting film in aposition to intercept the light rays' pass` ing through the transparent parts 15. Likewise patches of the reducing or restraining medium at 16, coperate with Athe corra strained until the proper amount of contrast' lspending transparent portions of the hair to produce a positive print having the proper color values. The printing quality of the clothing portions of thevnegative may be rewith the high lights is produced. .if desired, certain portions may be entirely eliminated from the picture, producing the effect ci' vignetting.

I .have found that the light-restraining medium may be coated upon the supporting film and evenly distributed thereon by means of a chamoiscovered spatula or thin broad stick, and a cotton swab may be used as a spreader. Where a very dense medium is desired the coatingupon front side of the iilm may be reinforced by a coating upon the reverse or rear side of the iilm as indicated in Fig. 3. In case it should be desired to reduce the density ofthe coating or restraining medium' or to remove it in any portion of the film, this may be readily accomplished f by using sponge rubber.

determined. Moreover the'adhesive medium' renders-the amorphous powdered material responsive to the operation of an eraser when it is desired to lighten or remove any of the material from` the film.

The many advantages of' my process of photographic printing will be appreciated by photographers. By my process the inaccuracies and undesirable features of a negative may be counteractedwith facility without the necessity for laborious retouching of `the negative. vMoreovenby my 4process negatives which were useless may loe-used to produce excellent positive prints. Again the relative effects of light and shadow may be varied to suit the individual taste of theA operator. Y i

Iclaim:- 1. The process of reproducing a desired relation between the highlights and shadows in a photographic picture which consists in interposing a translucent sheet between the negative and the source of light spacing saidtranslucent sheet 'from the negative, applying to Vsaid sheet a coating of plastic adherent amorphous material, the

separate particles of which are at all times readily removable from each other and from said sheet to vary the density or extent ot the coating, and manipulating said plastic adherentcoating to cause itsA extent to correspond to the portions of the 'negative through which it is desired. to restrain the actinic effect of the light-and 'its density to vary with the transparency of vthe correspondiiig adjacent portions ofthe negative. n

2. The process of reducing the contrasts between the high lights and shadows in printing positives from photographic neg atives which comprises interposing between the source of light and the negative a trans lucent lilin, spacing said film from the megative and placing upon said film a piastic adherent light-restraining medium in alinement withthose portions of the negative containing the shadows through Vwhich it is desired to restrain the actinicl e'ect 0I" the light, and varying the density said ad herent medium to correspond with the trans.- parency of the corresponding adjacent poitions of the'ne'gative, the treated translucent iilm being spaced from the negative a distance productive of coalescent diiiusion oit minute shadows cast by either the transiucent filmer the light-restraining medium thereon.4

8. The process of producing a desired relation between high lights and shadows in a photographic picture and copnterac'ting theu'ndesirable eiiiect of portions oi negatives, which comprises interposing a supporting light-transmitting sheet between the source of light andthe negativeand in spaced relation to the latter, spreading onl said sheet a lightj toning down coatingof amorphous powdered carbon combined with a plastic adherent vehicle, and restricting thef coating -to those portions of theV sheet'matching the portions of the negative through which it is desired to restrain the actinic eect' ioi the or false tone values, which consists in placi ng a shoet'of translucent In'aterial in spaced relation to the back of the negative, then producing upon said sheet a coating of readily removable light toning-down material opposite those parts of the negative that print too deeply, the coating being graded in density inversely to the thinness of the said parts ot' the negative, and then subjectingr photo-sensitive material to the action of actinic light transmitted through the treated sheet and the negative While in spaced f relation.

5. The process of modifying` the printing effect of a photographic negative Which eonsists in placing a sheet of lighttransniitting material in spaced relation to the face of the negative remote from that from which the ,f.; 'nts are to be taken, and then applying x light toning-down material to the sheet in locations matching those parts of the negative to be restrained 1n prlnting effect.

6. The process of producing photographic prints from negatives having faulty gradation, which consists in treating a sheet ot' translucent material of substantially equal light'transmitting quality throughout, with light restraining material in positions and density With respect to the faulty portions" of the negative in inverse relation thereto, and subjecting a photo-sensitive medium to the' action of actinic light transmittedv through the treated sheet and the negative, in the order named, With the sheet separated from the negative by a shallow air space and with the treated 'parts of the sheet in substantial register with those portions of the negative to be restrained.

In testimony whereof I aliiX my signature in presence of two Witnesses.

JOHN H. SNAPR Witnesses:

E. C. BROWN, E. E. WEAVER.

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