Far too much time has been given, and far too much importance has been hitherto attached, to the subject of optics in connection with photography. Much time and expense would have been saved had the pioneers of photography had good art educations as well as the elementary knowledge of optics and chemistry which many of them possessed, for without art training the practice of photography came to be looked upon purely as a science, and the ideal work of the photographer was to produce an unnatural, inartistic and often unscientific, picture. It is, indeed, a satire on photography, and a blot which can never be entirely removed, that at the very time the so-called scientific photographers were worrying opticians to death, and vying with each other in producing the greatest untruths, they were all the while shouting in the market-place that their object was to produce truthful works. At length, when the most doubly patented distorting lenses were made to meet their demands, they, with imperturbable self-confidence, presented a sharp, untrue photograph, insisting upon its truth. “A truer picture,” said they, “than drawing;” “truer than the eye sees,” some said. In short their picture was absolutely perfect. When a lens giving a brilliant picture, with all the detail and shadows sharp, and the planes all equally sharp, was at last produced, the scientists were in excelsis. But, alas! they proved themselves as unscientific as they were inartistic! Had they but taken up their simplest form of lens and used it as a magnifying-glass, they would have seen immediately that all was not right, and instead of clamouring for the artistic falsities of “depth of focus,” “wide-angle views,” “sparkle,” and the other hydra-heads of vulgarity, they might have set to and made the lens which was required. It was but a simple thing that was required.
Dallmeyer’s long-focus landscape lens.
The question then arises—What is the best lens for artistic purposes? That lens is Dallmeyer’s new long-focus rectilinear landscape lens. This summer (1888) we used one of these lenses and were delighted with it.
Why this lens is the best.
Why is this the best lens for our purpose? is the question that naturally arises. It is the best because being what is called a long-focus lens, it cannot be so ignorantly employed as can lenses of shorter focus, there is no appreciable marginal distortion, and with open aperture the outlines of the image are softly and roundly rendered, and in addition the relative values seem to us to be more truly rendered by it.
Best focal length to use.
This lens then being, as we think, the best for artistic work, the next question that arises is what focal length of lens must we use to get the best results. The student will be told ad nauseam that if he places his eye at the distance of the focal length of the lens from the photograph he is inspecting, all will be well. Such, however, is not always the case. He may prove it for himself by taking a lens of short focus and photographing any suitable object placed too near to him, and he may then place his eye at the distance of the focal length, and if he be an artist, he will immediately detect that the drawing is false, and the distance is dwarfed and pushed together as compared with foreground objects, whilst in a true drawing the proportions must be true between the foreground objects and distant objects. This misuse of the lens is what leads to the production of so many photographs false in drawing, and it is evident that since many of these falsely drawn photographs have been and are a basis for many scientific purposes, the deductions based upon them will have to be reconsidered.
Experiment for
finding a
rough
rule for
the use of
lenses.
The next question is, what proportion, as a rule, should the focal length of the lens bear to the base of the picture to give approximately true perspective delineation? This proportion should be as two to one, that is, the focal length of the lens should be as a rough working rule twice as long as the base of the picture. We arrived at the result by making a series of drawings on the ground glass of the camera, and comparing them with a perspective drawing made upon a glass plate. Opticians have arrived at the same conclusion, for we find this is the rough rule stated by Mr. Dallmeyer in his “Choice Lenses.”