Popular Science Monthly/Volume 6/April 1875/On the Correctness of Photographs
|ON THE CORRECTNESS OF PHOTOGRAPHS.|
By Dr. HERMANN VOGEL,
PROFESSOR IN THE ROYAL INDUSTRIAL ACADEMY OF BERLIN.
IN the previous chapters we have become acquainted with the development and the theory and practice of photography, and have mentioned cursorily various of its applications. It is our present purpose to give special attention to one point which is of great import in judging of the value of a photograph.
Most persons have a fancy that the application of photography is always uniform, whatever may be the object to be taken, and, therefore, that a photographer who can take a portrait must be able to take equally well a machine, a landscape, or an oil-painting. This results from the erroneous notion that the picture makes itself when the photographer opens and shuts the lid. But our readers know already that the picture does not make itself, but that it must be first developed, brought out, fixed, and copied. In all these operations there is no precise measure or rule how long the photographer should expose to the light, develop, fortify, copy, and tone the picture. This depends on his option and judgment; and he is able at pleasure to bring out the picture more or less in detail, according to the time of exposure. Again, he can make it more or less brilliant, according to the degree of strengthening; he can make it more or less dark, according to the mode of imprinting; more or less blue, according as he tones it down. But what is it that directs his judgment to determine if the picture is correct or not? It is Nature, and Nature alone! He must know Nature, and compare it with his picture. Nor is this easy. Nature appears positive to him, but in the picture she appears first negative; and, if he compares the two, he must be able in his mind to convert the picture, that is, to change it and represent it as a positive, which it is afterward to become. More comparing and study is required to do this than is generally supposed.
If two printed proofs are presented to a man who is ignorant of the art of printing, one of the sheets in question being well and the other ill printed, if the defects be not too glaring, this person will not be able to detect any difference between the proofs. Far otherwise is it with the practised eye of the printer, who immediately detects that in one proof the type is too thick, or thin, or leaded, or that the letters are faint, or blotched, or uneven. In like manner, a practised eye is needed to judge a photograph—an eye not only able to detect the finest details of the picture, but also the peculiarities of the original. The unprofessional man often uses the expression, “I have no eye for it”—that is, “I am not accustomed to see such things”—and it is in this manner that we first discover how imperfectly we use this, the most perfect of our senses.
A man born blind, and who receives his sight by an operation, cannot at first distinguish a cube from a ball, or a cat from a dog. He is not accustomed to see such things, and must first exercise his eyes and learn to see.
We, also, though in possession of sound organs, are blind to all things that we are not accustomed to see; and this fact is most apparent in art, as also in photography, so closely related to it.
If photographers principally engaged in taking portraits are not able to produce a good landscape, the reason of this is that they have no eye for landscape—that they consider a picture to be good after too short an exposure, or when imperfectly developed and strengthened, or when inaccurately printed. It proceeds from their not knowing the influence exercised by the position and intensity of the sun on the aërial perspective produced by clouds, without speaking of other points of less importance.
Thus every class of subjects requires a special study, though the manipulation of photography remains in all cases the same; therefore, there are photographers whose proper province is portraits, and others devoted to landscapes, to the reproduction of oil-paintings, etc.
The remark is frequently made by admirers of photography, that this newly-invented art gives a perfectly truthful representation of objects, understanding by the term truthful a perfect agreement with reality. Photography can, in fact, when properly applied, produce truer pictures than all other arts; but it is not absolutely true. And, as it is not so, it is important to become acquainted with the sources of inaccuracy in photography. Many exist. I shall treat here especially of optical errors.
The lenses which are employed in photography do not always give absolutely true pictures. Suppose, for example, that a simple lens receives the impression of a square; it often represents it with curvilinear sides, as in the diagrams A, B, C (Fig. 1), though with a feebler outline. A picture thrown off quite out of drawing by such a lens, in which straight lines turn out as curves, is evidently inaccurate. The inaccuracy may not be felt by many, but it exists. It may perhaps be expected that this defect disappears in the case of what are called correct lenses, but let the attempt be made to obtain a view with these correct lenses of lofty buildings taken from a low position. The lines that ought to be perpendicular commonly converge upward. This is caused by the photographer being obliged to direct his instrument at an acute angle upward, in order to be able to take in a view of the whole building. In doing this, perpendicular lines project themselves, converging upward. To avoid this defect, lenses have been made with a very large field of view. These are called pantoscopes. But these reproduce distant objects apparently on a very
small scale, and objects near at hand on a very large scale—peculiarities unnoticed by unprofessional persons, but detected by close observers of Nature.
A remarkable phenomenon, exciting the wonder of the uninitiated, is the distortion of spheres in photography. Let the reader imagine a row of cannon-balls; these will always appear balls to us, and the artist will always draw them as a circle. But, if they are taken through a lens with a large field of view, the balls situated near the rim of the lens no longer appear circular, but elliptical.
To explain this phenomenon, we must attend once more to the mode in which the picture is produced. Let it be conceived that there are three balls, A B C, in front of a camera, K, with the lens o (Fig. 2). Each ball projects a cone of rays on the optical centre of the lens. This is continued within the camera, and cuts the surface of the picture, if its axis falls obliquely upon it, in the form of an ellipse, such as A C. Only, if the axis of the cone of rays is perpendicular to the surface of the picture S S, as at B, the picture appears a circle. I admit that this defect only occurs when the field of view of the lens is very large, and the balls are situated very near its rim.
A photographer brought to the author the picture of a castle having a row of statues in front of it, which he had taken with a lens having a large field of view. Singularly, the heads of the statues toward the margin became continually broader, and similarly their bodies; and the slim Apollo-Belvedere, who unfortunately stood on the very edge of the margin, had such full-blown cheeks and so protuberant a paunch that he looked like Dr. Luther.
But, quite independently of these considerations, there is another point that must materially affect the accuracy of photographic representation. Photography generally gives the light parts too light, and exaggerates the dark shadows. This is a fundamental error which is associated with their very nature, and which it is very difficult to avoid. It is seen in the most evident manner in taking objects lighted by a brilliant sun; for example, a statue. If the exposure is short, a detailed picture is obtained of the light side, but the shady side is a black daub or blotch. If the exposure is long, the shady side is full of detail, but the light side exposed too much, and so thickly covered that the details are wanting in it. Hence photographers are often driven to subterfuges if they wish to obtain a correct picture; they are obliged to mitigate the contrasts—to make the light more toned down, and the shades lighter than painters are wont to make them. The latter often exclaim when they see the photographic exposure of a model, and wonder if the picture will be correct. And no doubt, in the case of landscapes and architecture, the results are not always satisfactory.
The author once took a photograph of the interior of a laboratory. It presented the appearance of an ordinary vaulted hall. All was quite excellent. The tables, stones, retorts, lamps, etc., were all seen, only the vaulted ceiling was quite dark. New attempts were made, with exposures of twenty, thirty, or forty minutes. At length a trace of the vault appeared; but now the objects in the vicinity of the window were suffering from too much exposure; that is, they had become as white as if they had been snowed over. This circumstance of photography exaggerating the dark parts appears again in very simple matters, such as the reproduction of copper-plates. A photographer once reproduced a painting of Kaulbach's “Battle of the Huns.” He produced a charming photograph, but the city in the background appeared too thick and black, and not sufficiently toned off. The customer refused the photograph and demanded another. The photographer made another attempt, giving a longer exposure, and now the distance appeared softened down; but, unfortunately, the objects close at hand, which had to appear black and clear, turned out gray. In the end, the photographer escaped from the difficulty by negative retouche. These are quite ordinary examples to show how difficult it is to reproduce an object correctly.
But we come now to the worst point, that of color. Photography gives the cold colors—blue, violet, and green—too light, and the warm colors too dark. Take as an instance the photographs on sale of “Sunset on the Ganges,” by Hildebrandt. It represents a red glowing sun, with clouds of chrome-yellow on an ultramarine sky. But what becomes of all this in the photograph? A black round disk between black thunder-clouds. It looks like an eclipse at Aden. The difficulty of representing Nature is still more patent when the photographer attempts to grapple with higher artistic questions. Let us take an example. There exists a pretty genre picture called “A Mother's Love.” A mother sits reading in an arm-chair; her little darling embraces her suddenly from behind, and, delightfully surprised, she drops her hand with the book, turns to look at her little pet, and offers her cheek to the little boy to kiss.
A photographer was inspired with the idea of producing a similar picture with the help of a living model. He found a comely maiden, who agreed to personate the mother, and a good-looking boy was also found. An arm-chair for the mother, a chair, and other suitable furniture, were easily procured. The next point was the grouping. The pseudo-mother was very accommodating to the requirements of the photographer, and even assumed a look which, for want of a better, might pass as the expression of a mother's love. But the boy was not of the same mind. He was by no means attracted by the pseudo-mother—he protested against coming near her, and a good cuff was needed to make him take up the requisite position. Time was thus lost. The mother began to feel uncomfortable in the irksome position, straining her neck. The photograph was taken at last, and turned out sharp and without spot or blemish. The models were dismissed, to their great satisfaction. What was the result? The boy was embracing his mother with a face bearing evidence of the cuff he had received, and with a look as if he would have liked to murder her; and she regards him with an expression that seems to say, “Charles, you are very unmannerly,” and appears greatly annoyed that her pleasant reading has been interrupted. Can it be said that a picture of this kind correctly expresses the intention of the artist? Does the picture thus produced correspond accurately to the legend, “A Mother's Love?” The untruthfulness of such a picture will be evident to every one.
Thousands of pictures of this class are offered for sale. About ten years ago errors of this kind were committed by the thousand in stereoscopic views, and if they meet with approval this must be referred exclusively to the bad taste of the public. But it may be said in this case it is not the photographer who is guilty, but the unwilling models.
Nevertheless, it is this very circumstance that throws such immense difficulties in the way of taking good photographic portraits. Many persons by no means wish that their characters should be correctly given. The rascal wishes to appear an honorable man in his picture; tottering old men desire to appear young, foppish, and lively; the maid-servant plays the fine lady in the atelier; the tradesman's daughter would be a court lady, the street-sweeper a gentleman. Thus the picture serves them only as a means of flattering their personal vanity; and, in order that these people may appear very noble and distinguished, they put on a Sunday's dress, often borrowed and a very bad fit. They practise at home, moreover, before their looking-glass, in the presence of papa, mamma, wife, or lover, impossible attitudes in an artistic point of view. Even cultivated persons are not exempt from these absurdities. Thorwaldsen relates of Byron, who gave him a séance, “He sat down opposite to me, but assumed, immediately I commenced, a perfectly different expression. I called his attention to this. ‘That is the true expression of my face,’ replied Byron. ‘Indeed,’ I rejoined, and then made his portrait exactly as I wished. All persons declared my bust to be an excellent likeness. But Lord Byron exclaimed, ‘The bust does not resemble me; I look much more unhappy.’ The fact was, that at that time he wished to look intensely miserable,” adds Thorwaldsen. The photographer is even in a worse case. If Byron had come to a photographer, and had presented his face of misery to the camera, what could the photographer have done? He is unfortunately dependent on the model, and many models leave him in the lurch at the critical moment, often not intentionally, but from nervousness or inadvertence. Much depends here on the influence of the photographer, who must know how to control his sitters with courtesy; but many portraits fail without any fault on his part. The author has often witnessed how persons of his acquaintance, at the moment of being taken, assume quite a strange expression without being in the least aware of it.
There are still more characteristic cases of photographic inaccuracy which cannot be attributed to the models. Let us suppose that a photographer, stimulated by the beautiful pictures of Claude, Schirmer, and Hildebrandt, wished to photograph a sunset. He evidently can only expose his plate for a moment to the dazzling bright sun. What sort of a picture is the result? A round white blotch and some shining clouds around it. That is all that appears clearly. All objects in the landscape—trees, houses, and men—have had too short an exposure, and form a black mass. There, where the eye clearly distinguishes road, village, forest, and meadow, it sees in the photograph nothing but a dark patch without any outline. Is such a picture true? Even the most fanatical enthusiast of photography will not dare maintain this.
Such cases, where violent contrasts of light and shade make the production of a correct picture quite impossible, are countless in number. Let any one examine the majority of the photographs of the white Royal Monument in the Thiergarten at Berlin. The monument is excellently given, but the background of trees is a confused black mass, without details, without shades of tone; the architecture and other features are there, all except the splendid foliage that delights the eye at that spot. Still more numerous are the photographs of rooms, in which the dark corners, quite discernible to the eye, present nothing but pitchy-black night. There are other cases, besides these, of photographic incorrectness.
Suppose we are looking at a mountain landscape. A small village, inclosed on both sides by woody hills, occupies the centre, its houses extending along the declivities and scattered picturesquely among the trees. A ridge of finely-broken mountains in the background, their summits shining in the setting sun, frames in the wonderful picture, whose effect is only injured by one object—a ruinous pig-sty close to the spectator, with a dung-heap beside it. A painter, wishing to paint this scene, would certainly have no scruple about altogether leaving out the pig-sty, or leaving it so indistinct and dark that it would not injure the landscape. But what is the photographer to do? He cannot pull down the offending object. He seeks another position; but there the greater part of the landscape is concealed by trees. He ends by admitting the pig-sty, and what kind of picture is the result? On account of its vicinity, the pig-sty appears of colossal size in the picture. On the other hand, the landscape, which is the principal thing, appears small and inconsiderable. A still more fatal adjunct is found in the dung-heap occupying almost one-fourth of the picture. As the most brightly-lighted part of the photograph, it immediately attracts the eye of the beholder; it diverts his glance from other important points; it acts as a disturbing influence. The photograph obtained does not appear as a picture of the landscape, as it ought to be, but as a view of the pig-sty! The accessory has become the principal point. The picture is untrue. It is untrue, not because the objects it represents were not present in Nature, but because the accessories are presented too glaringly and too large, while the principal parts appear too small, indistinct, and inconsiderable.
This brings us to a weak point in photography, which represents accessories and principal features as equally defined. The plate is indifferent to every thing, while the genuine artist, in reproducing a view of Nature, gives prominence to what is characteristic, and entirely keeps under or softens off accessories. He can dispose and manage it with artistic freedom, and he has a perfect right to do so, because, by his giving prominence to what is characteristic, and dropping what is accessory, he is truer than photography, which gives equal prominence to both, and often more to what is accessory. Reynolds says of the portrait of a lady in which an apple-tree was most carefully painted on the background, “That is the picture of an apple-tree and not of a lady.” Similar remarks might be made on seeing many photographs. It is a cardinal error in their case, that they give a stronger tone to accessories than to essentials. They present a conglomerate of furniture, and it is only after careful inspection that a man is detected sticking among it, whose portrait is to form the picture. In another case a quilted white blouse is seen, and it is only after some time that a girl's head is perceived rising above it. A park is seen in a landscape, with fountains and other adornments, and it is only after some time that a black coat is seen confounded with an equally dark bush.
It may, perhaps, excite surprise that the writer ascribes greater truth to painting than to photography, which is generally regarded as the truest of all methods of producing pictures. It must be self-evident that the remark has only been made in connection with works of the first masters. One of the great services of photography is that it has rendered impossible those daubs of inferior artists formerly offered for sale in every street. But the perfect picture of the photographer is not self-created. He must test, weigh, consider, and remove the difficulties which oppose the production of a true picture. If his picture is to be true, he must take care that the characteristic is made prominent and the accessories subordinate. The non-sensitive plate of iodide of silver cannot do this. It receives the impression of all that it has before it, according to unchangeable laws. The photographer attains this end, on the one hand, by appropriate grouping of the original; on the other, by a proper treatment of the negative. I admit that to do this he must also be able to detect what is characteristic and what accessory in his original.
Therefore, whoever wishes to undertake any photographic production must first become familiar with the object that he wishes to take, that he may know what he has to do. The photographer will not, indeed, be able to control his matter, like the painter, for the disinclination of models and the optico-chemical difficulties often frustrate his best endeavors, and hence there must always be a difference between photography and a work of art. This difference may be briefly summed up by saying that photography gives a more faithful picture of the form, and art a more faithful picture of the character.
- Abridged from the “Chemistry of Light and Photography,” No. XIV. of the “International Scientific Series.”