IT remains to say a few words on the all-important subject of art as connected with photography. There are those. who affirm that photography is not an art, and the photographer there-fore not an artist. Well, it is certainly true that every operator with the camera and the prepared plate is not an artist; but to say that photography, in its function of picture-producer, is not an art, is surely to make light of the meanings of words. There is, of a truth, no art in carrying about and manipulating an automatic view-taker, any more than there is science in heaping specimens higgledy-piggledy in a cabinet. But when certain means are carefully and deftly employed to the attainment of a given end, there is certainly art, and art of a high order, if these means are used with intelligence and taste. But therein lies the difference. Many have taken up photography thinking that in a cunning box of mechanics lay the royal road to art ; but their disillusionment was speedy and thorough.
” Some years ago,” says the author of a recent magazine article, “when amateur photography was in its infancy here (i. e., in the United States) as well as in other countries, a soulless corporation extensively advertised a camera which only required a button to be pressed and pictures were made. The idea soon took root that there was nothing in photography, when it merely required the pressing of a button. It was apparent that any fool could do that. And when these cameras were purchased and tried, the result convinced the owners of the fact, not only that any fool could do it, but that he was a fool a good many sizes larger for doing it. A feeling of disgust and disappointment was created, and there is little doubt but that photography was taken up by thousands and dropped again when they found out how it has been misrepresented to them: I firmly believe that many of these, had they thoroughly understood what was required to become a successful photographer, would have taken the matter up properly with the determination to master it thoroughly, and would eventually have succeeded.”
That is an extreme way of putting the matter, though undoubtedly true; yet there is salvation even for a buttonerif he has eyes to see and a heart to desire the perfect thing. For therein lies the whole of art. What the photographer needs first and foremost of all is to perceive and understand the limitations of his art. It does not afford him the wide scope and comprehensive gamut of the palette; in some respects even he is more circumscribed than the artist in black and white. He cannot to the same extent impress his character upon his work ; but he can go much deeper into his subjectif he will only patiently find out the waythan either the spectrum-wielder or the handler of monochrome merely.
His difficulties divide themselves into two departments. In the first are the technical difficulties which he will have to overcome, and which have been set forth in some detail in the foregoing pages ; in the second stand the elementary laws and principles of art, which can only be learned from masters or by the diligent study of books devoted to the subject.
” The gravest difficulty which he will have to surmount, and the one in which he can least profit by outside help, will be the realisation of the fact that he is producing a monochrome rendering of a coloured subject, the training of his mind to dissociate colour from his subjects and to see their monochrome value; but unless this difficulty is surmounted, he will often be deceived by the beauty of a view which will appear entirely uninteresting when rendered in monochrome, by a process which does not even give to each colour its true value.”
This question of the true rendering of a subject in monochrome is a very important one, and as it enters very deeply into the art side of photography, it has been thought well to reserve its treatment to this portion of the work.
When referring in a previous chapter to the action of light upon the sensitive salts, it was pointed out that, while the yellow region of the spectrum is the brightest to the eye, and the blue and violet region the feeblest in luminosity, it is nevertheless these latter rays, which in photography have the predominant effect on ordinary plates. It is manifest therefore that, the resulting monochrome cannot represent the real colour values of the various parts of the object depicted. In other words, the picture obtained is not a true one.
To take an instance: In a sunset sky or a yellow flower there will probably be little or no blue, while the yellow is prevalent and very luminous. If, therefore, these two objects be photo-graphed, first with a substance or combination most impressed by the yellow, and then with one which is more sensitive to the blue, it is evident that the former will yield a more truthful monochrome print than the latter.
In taking subjects that depend for their effect to a considerable extent upon colour, such as those above named, this lack of sensitiveness to certain colours was long greatly felt, especially as regards the reproduction of paintings, and gave rise to much speculation and experiment with a view to overcoming the defect. It was not, however, until Dr. H. W. Vogel of Berlin made, in 1873, the discovery that the addition of certain dyes, like coralline, changed the maximum of sensitiveness of the spectrum, that a partial remedy was found. Eder and Abney, as well as others, followed up his experiments, with the result that what are known as isochromatic or orthochromatic plates, that is, plates more sensitive to the yellow and red rays, were soon available for practical work, to the undoubted improvement of representations of coloured subjects in monochrome.
Without going too much into technical details, it may be stated that an ordinary plate is most sensitive to the spectrum midway between the violet and blue rays. If, however, such a plate be slightly coloured with erythrosin, one of the erosin group of dyes, the sensitiveness of the region betwixt the blue and the yellow will be intensified, the result being that the greens will be more truly rendered. If it is desired to extend the sensitiveness further towards the red another dye must be employed, such as cyanin, which in combination with erythrosin will continue the sensitiveness to the yellow, and through the orange towards the red end of the spectrum.
The action of these dyes has not been fully ascertained. Vogel designated some of them ” optical sensitizers,” and he explained their action by supposing that when the dyes absorbed the light some sort of secondary action takes place. Abney and other authorities, however, take exception to this theory, being rather of the opinion that an organic silver salt is formed, and that this salt may be sensitive to rays of the spectrum to which the inorganic salt is insensitive, or it may increase the sensitiveness of the inorganic salt for some particular part of the spectrum. The fact that when a plate has been immersed in a solution of the dye it may be washed until all visible trace of it has vanished without in the least reducing its sensitiveness to colour seems undoubtedly to indicate the formation of an organic silver compound.
Whether this is the right explanation or not the fact remains that the dyes render the plate sensitive to the rays they absorb.
Many other dyes besides those mentioned are available and are being had recourse to more and more. They include malachite green, cerulean, and alizarin, which are used for sensitizing the red.
But whilst a plate’s sensitiveness to various colours may thus be augmented, the original sensitiveness of the different rays of the spectrum is not eliminated; it is indeed so much greater than the sensitiveness imparted by the organic dyes that the latter would be almost completely nullified were it not possible at the same time to reduce the action of the blues. This can be effected by making exposure through a screen of yellow glass, or, in the case of a picture, by illuminating it with yellow light. If we take a water-colour drawing or a painting representing, for instance, a spring landscape, we shall see that its usually prevailing colour is green, with a large admixture of yellow. To reproduce this in monochrome with fidelity to its colour values it will be necessary to use a plate that is sensitive to the region of the spectrum between the blue and the orange, as well as to the blue itself, though the energy of the blues must be moderated. If we look at an azure sky through a piece of yellow glass it will be seen that the blue will be converted into a more or less decided green. Hence by making the exposure for the spring landscape through a yellow screen, the sensitiveness of the greens and yellows will be intensified and the action of the blue reduced, and thus a truer monochrome result.
One way of attaining this end is to allow daylight to pass through light yellow paper or glass; another is to coat the surface of the lens with a film of collodion to which a slightly yellow tinge has been communicated.
” If,” says Abney, ” a landscape be taken with these dyed plates without yellow glass intervening there is very little difference between the result and that obtained on an ordinary plate, the reason being that the objects reflect a large proportion of white light, and that the blue light in this reflected light is that which is most effective. If, however, a yellow glass be placed in front of the lens, the photograph will differ considerably in appearance. The blue of the sky, for instance, in the resulting print, will be rendered a grey instead of white, whilst a white cloud will be white. The greens of the trees and grass will be more harmonious, and so will any yellow object which may be in the view.”
Since the above was written, however, another experimenter has obtained results which justify him in saying that gelatine-bromide plates immersed in a solution of auromine containing a small proportion of erythrosin are sensitive to all colours, including red, and give an approximation to correct colour values without the use of a screen.
The makers of orthochromatic plates do not usually state by what method they are prepared, nor to what colours they are specially sensitive. The photographer therefore has to work in the dark to some extent until he has found out their qualifications by experiment. Hence, when the light-wielder does not mind a little trouble, he will find not a trifling advantage in preparing his own orthochromatic plates. For suchand there are amateurs enthusiastic enough to take any amount of pains when there is a definite object to be attaineda full description of the process is given by Burton in his ” Modern Photography.” Some useful directions are also contained in ” Photography : Artistic and Scientific “a very interesting and highly useful work.