US1724445A - Color photography - Google Patents

Description

Aug. 13, 1929.

w. R. WHITEHORNE 1,724,445

COLOR PHOTOGRAPHY Filed Aug. 24, 1925 2 Sheets-Sheet. l

COLC RED RED COLORED YELLO W COLORED BLUE mm! X! low a: Green fled N YGHOW Blue g- 13, 1929- w. R. WHITEHORNE 1,724,445

COLOR PHOTOGRAPHY Filed Aug. 24, 1925 2 Sheets-Sheet 2 sown YELLOW COLOD BLUE COLORED RED and involves a method Patent Aug. 1, i929.

Application filed August 24, 1925. Serial No. 58 ,000.

to color hotography by which such photographs can be taken and prepared with a minimum of time and a maximum of accuracy in color reproduction.

My invention may be differentiated from former methods first by the general statement that it does not depend upon the use of screens o r filters. The advantage of this in the saving of time and the simplification of My invention relates apparatus is obvious. My invention is perhaps most particularly characterized by my use of one or more plates, films or other sensitized media which are particularly insensitive with regard to certain parts of the spectrum. The matter of differentiated sensitiveness, generally speaking, is not new, but in my invention this matter of a special or characteristic insensitiveness is made "to play a somewhat difierent part than has heretofore been accomplished or attempted.

I have found that lat-es sensitized in certain manners, as will be hereinafter discussed, may be thereby rendered relatively insensitive to certain colors or wave lengths so as to show a very marked or characteris tic band as readily ap rs from the spectrogram. Such plates ive 11 developed for photography of special subjects, butusually with particular reference to their photographic power in general regions. This is usually obtained at the-expense of lack of sensitiveness in certain other regions, which lack of sensitivenes's while unde(s1i1il'1abl e, lilas not bgelan a serious defect for or a oto a 'c oses.

In a ofdance wi th my i ngention I utilize this very incident of insensitiveness as a means of obtaining the desired color effect, that is to say, by deliberately employing a plate which is quite definitely insensitive to a certain color I am able by my method to intensify that very 'color in my ultimate picture to which a selectal plate is comparatively blind.

As is well known to those shlled in this art, there is great dificulty in obtaining aings to illustrate certain characteristic media and those steps by which such photographs can be produced. To these I shall make reference by the usual characters similarly applied throughout. In the drawings I have selected as an object to be photographed what may be considered as a childs all or plaque striped in difierent colors. While this does not involve the depiction of intermediate colors or shadings, it is believed that the production of these intermediate effects will'be seen by those skilled in the art to follow naturally according to the principles disclosed. In these draw s: a

Fig. 1 is intended to represent an object such as a disk or ball s'tripd vertically in difierent colors. Figs. 2 and 3 atives thereof. Fig 4 is a diagrammatic illustration of a composite or doubling of these negatives.

Figs. 2", 3 and 4 indicate s tograms showing the light intensities of this plates. Figs. 5, 6 and 7 indicate prints from the plates of Figs. 2, 3 and 4.

Figs. 8, 9 and 10 represent these prints as Q tonw or dyed.

Fig. 11 indicates the transmitted color valuels of these three printswhen superimpose V I Figs. 12, 13 and 14 represent a pair of negatives and their composite dia m corresponding to Figs. 3 and 4, but involving modified procedure.-

Figs. 12, 13 and 14 indicate a spectrogram of the light intensities of the plates, dicated in the pr Figs. 12, 13 and 14.

Figs. 15,16 and 21 represent prints there, from corresponding to Figs. 5, 6 and 7.

Fig. 17 indicates a print from the plate. of Fig. 21, giving its reversal.

Figs. 19 20 and 18 represent the'colored prints of Figs. 15, 16 and 17, and

Fig. 22 represents the transmitted lightvalues of the sluiperimposed colored prints.

The object selected for convenience of illustration and while its colors are handed rather than otherwise distributed, as in most pictures or scenes, it will be unde that the princi-- ples involved are the same.

As suggested earlier herein, m method offers unusual possibilities for ection in shown in Fig. 1 is merely be then made in the reproduction of predominant or important colors in any selected subject or view to be photographed. While therefore the object X shown in Fig. 1, does not call for any particular intermediate color treatment, we may assume that it is desired to favor a green color as would be the case if a landscape was taken in which trees and plants predominate.

In order therefore to favor the green or its important component yellow, I employ a plate B which has been bathed or otherwise prepared with a solution which renders it substantially insensitive to the green yellow region. This may be readily seen in a spectrogram as indicated in Fig. 3 which shows a broad bright band through this region.

With this plate I use a plate A, which may be an orthochromatic plate, which shows a considerably differentiated spectrum band as indicated in Fig. 2. These plates may be exposed in any desired manner. Very conveniently they may be assembled in tandem in a pack or loaded into a plate holder in superlmposed position and the picture may the usual manner in an ordinary camera at substantially the same speeds that ordinary pictures would be taken.

While I mention this superimposed exposure of the plates as convenient in the practice which I have followed as it assures registry of the prints, I would explain that any filtrative effect, such as has been heretofore stressed in certain processes depending upon filtration, may be relatively ignored, for the purposes of the present application, as my invention is not dependent upon such, an action and as such an action is wholly incidental to the more important factors which I will now describe.

While the two negatives A and B heretofore described are very considerably differentiated chromatically, and in one phase of my invention capable of use in two color work where it is desired to get more faithful reproduction of the natural colors a third color s stem is preferable as is general in color p otography.

In the practice of m fore, instead of attempting invention, thereto take a third negative at the time the lpictur is snapped,

I take my two negatives and B and superimpose them as diagrammatically illustrated in Fig. 4. In this figure it will be seen that the densities of the negatives or the indicated intensities in the s ctrum as indicated by the lighter portion in Fig. 4, is very much narrower and a print from the superimposed negatives A and B gives a print or positive 1n which the yellow is very strongly accentuated as indicated in Fig. 7.

If new prints be taken from negatives A and B, the prints will appear substantially as shown in Figs. 5 and 6, in which the stripes are considerably differentiated.

These prints 5, 6 and 7 may be considered as lantern slide prints or may be of any other I then dye or tone the prints A B (AB) as for example, red, blue and yellow, respectively, as indicated in, Figs. 8, 9 and 10.

If now these plates or members indicated in their dyed condition as A B and (AB) are superimposed the transmitted light Will make the object photographed come out sub stantially in its original color as I have attempted to indicate in Fig. 11. In that figure it will be seen that the black stripe of the ball having comeout strong in each of the prints shows the combined red and yellow very much darkened by the blue, so that the effect is a dark brown which is supposed black in value. The green stripe is'made up of the superimposed blue and yellow of prints B and (AB) which by reason of their careful selection may be made to show the desired green with very great faithfulmaterial adapted for the purpose.

ness. The red stripe is clearly presented by 1 the red of plateA The yellow is strongly presented by the plate (AB) 2 and the blue by the plate B It Wlll be particularly noted that the yellow of the plate (AB) 2 comes from the overlap of the spectrum values ofplates A and B,

so that the ultimate slide member comes out which was the very color to which the sensitized plate B was blind.

The plate selected for representation as plate B and as indicated by the spectrum diagram 3 happens to be what is known as a .pinorthol, which happens to give the particular band shown in the spectrum. In certain circumstances where some colors other than green appear prominently, it might be desired to furnish plates of different characteristics for the purpose of favoring thosestantially insensitive to the color desired, by

taking a print from the combined negative so .with a very particular definition ofyellow Ill as to secure a narrowing of the bright band in the combined spectrum.

In the procedure which I will now describe I will discuss a method by which I take two plates which includes one which is considerably sensitive to the color desired, but insensitiveto some other color. I then proceed to take my composite negatives as indicated in Fig. 14, but take from them a print which reverses the values and using this print as indicated in Fig. 17 as a negative, produce an ultimate print as in Fig. 18, which I use for the color to be less favored, as will be seen by the following.

If the plate A indicated in Fig. 12 be an ordinary plate, dyed for example with pinacyanol blue, its spectrogram (indicated in Fig. 12) will be dark in the red generally and dark in'a narrow band of the blue green. As indicated in Fig. 13, the spectrogram of plate C while having a bright band in the red is sharply cut off between the blue and the red. In the composite therefore the print (AC) will be light in the red and dark in the blue, while the print (AC) 2 (Fig. 17) from (AC) (Fig. 21) will be dark in the red and light in the blue.

The print A shown in Fig. 18 is then dyed or toned red; the print C (Fig. 19) is dyed or toned blue; and the print (AG) (Fig. 20) is dyed or toned yellow.

Transmitted light of these combined plates will show a very good red and a somewhat yellowish green, or in other words, will express to advantage the red-orange and yellows at the expense of the green.

It will be seen from these two examples that my method involves peculiar possibilities in its utilization of chromatic difierences in plates without screens, first, by a recognition of true possibilities of such difierentiation, and second, by what might be called an additive subtraction as in the case of the using of a composite plate, and third, by the additional step of reversal of the print from the composite negative to supply the third color.

As additional instances of my process, plates, or films may be made up as follows:

For a two color picture I preferably use what we may call a pinacyanol blue plate as heretofore referred to, and an ordinary or ortho chromatic plate. These give an excellent separation of the red from the blue and the result is very-satisfactory.

For a three color result from two plates, as hereinbefore described, I provide an erythrosine dyed plate and a pinacyanol dyed or a pinacyanol blue dyed plate. The latter is preferable for pictures in which there is a considerable amount of yellow. The erythrosine plate separates the yellow from the red better than the polychrome plate and the two plates of this character may be combined to produce a third plate as before described. v

Where exposure can be made using three plates or surfaces in the original exposure, I find very satisfactory results come from the use of an erythrosine plate, a pinacyanol blue plate and a pinacyanol. Where pictures are taken in succession I substitute a pinorthol II for the pinacyanol. Where the plates are exposed in tandem it does not or other color photographs from such negatives is simple and may be done by ordinary contact'printing and by ordinary methods of toning or dyeing. All such modifications and variantsare to be understood as within the scope of my invention which I have defined in the following claims.

What. I therefore claim and desire to secure by Letters Patent is: I

1. In sensitized media for color photography, a pair of sensitized surfaces having a common color insensitiveness in one region of the spectrum and a different color insensitiveness in another part of the spectrum.

2. In a systemof color photography the exposure of plural sensitized surfaces, one of said surfaces having a predetermined insensitiveness to. a desired group of wave lengths, in reversing the negative so formed and printing therefrom to secure a colorable member or color photograph.

3. In a system of color photography, the production of a pair of photo negatives from sensitized media having common color insensitiveness in one region of the spectrum and a difi'erent color insensitiveness in another part, and in preparing a print combining the efi'ect of the joint insensitiveness of the two negatives first mentioned.

4. In a system of color photography, the production of a pair of photonegatives including one of characteristic color insensitiveness, in producing a print fromthe composite negatives, and in preparing colored prints from the individual negatives and from the composite print.-

5. In a system of color photography, the production of a pair of photo negatives from sensitized media having common color insensitiveness in one region of the spectrum and a different color insensitiveness in another part, and in preparing a print combining the effect of the joint insensitiveness of the two negatives first. mentioned, and in taking colored prints from the said first mentioned negative and from the composite print.

6. In a system of color photography, the production of a pair of photo negatives including one of a redetermined color insensitiveness in pro ucing a third-print from the composite negatives," and in preparing colored prints from the individual negatives and from the composite print as a negative.

7. In a system of color photography, the

production of a pair of photo negatives each therefrom a third chromatically diflerenti- 15 having a common color deficiency in one ated member in color supplementing relation part of the spectrum and each having a difthereto.

ferent color deficiency in another part, and 9. In a multi-color photographic process 5 in preparing diflerently colored prints therethe making of two chromatically difierentifrom in predetermined supplementing chro: ated negatives, and in producing therefrom matic balance. three or more chromatically cooperative 8.In a multi-c'olor photographic rocess color plates for assembly.

the making of two chromatically difi erenti- In testimony whereof I aflix my signature.

:0 ated exposure members, and in producing WILLIAM R. WHITEHORNE.

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