Seeing and Believing

The distortions apparent in this Jacques Henri Lartigue photograph stem from two things. First, the design of the vertical traveling slit shutter exposes the top of the frame before the bottom, causing the top of the wheel to be exposed before the bottom. Second, Lartigue was apparently panning the camera to track the motion at a rate slightly faster than the car was actually going—so the wheel appears to stretch behind the car. The spectators were stationary, and appear to lean backward due to the change in camera position during the exposure. Photographic evidence like this, read without any understanding of the camera’s mechanisms, tend to produce some pretty strange conclusions regarding motion.

I am impressed by the strength of the conviction that the top of a wheel moves faster than the bottom in some late 19th and early 20th century accounts. Lartigue’s visual trick doesn’t appear to be that unique. Though Martin Aldur doesn’t assert that such a view is “true,” he does assume that it is accurate:

I remember seeing a photograph of a racing motor car taken with a shutter that was not sufficiently rapid for such a subject—thereby approaching more nearly the condition of human sight—which showed these two causes at work, for the spokes and rims of the wheels were distinct and exact where the tyre touched the road, but blurred and pulled forward at the top where they were advancing more rapidly.

The duty of the spokes, which are the legs of the machine, is to thrust the axle forward, just as the foot and leg thrust the horse forward. We are so inclined to watch the horse as it gallops that we think of it as swinging its legs to and fro past the indistinct landscape; we do not see the hoof stationary upon the ground propelling the creature forwards. Yet this is what actually occurs, and affects our impressions, so that as man or animal runs or leaps, fights or dances, a tail, a sword, a piece of drapery, a foot, a hand will sometimes seem to hover or lag behind, and make the limb appear too long, so that the artist in his truth to his impression will be led insensibly to see and use such accurate “inaccuracies” upon which the exact effect depends—inaccuracies as true as that colour is modified by the colour that is placed against it, or that a white flagstaff, which looks light against a house, looks darker and thinner where it comes against the evening sky above it, and must be so painted to give the effect, although we know it to be actually of the same tone throughout its length. And so it is not only for the pattern of the picture that the leg which is too long in Rubens, the limb which is “deformed” in Degas are right, but also in truth to the natural appearance for those who can see.

An artist to whom such changes are always evident will necessarily introduce them into his work, either so subtly as to pass unperceived by most people or so frankly as to shock and distract some spectators.
From “The Representation of Movement in Art” by Martin Aldur The Burlington Magazine for Connoisseurs, Vol. 23, No. 124 (Jul., 1913), 204-207.


Edison's Tasimeter

Thomas Edison, Infrared Pioneer

I ran across an unusual infrared light meter today in an article from Applied Optics, Vol. 18, No. 22, November 1979. It is interesting on several levels because it was not patented by Edison, who patented nearly everything he did, and was instead given freely to “science.”

The little-known episode deals with Edison's participation as an IR astronomer in the Draper Eclipse Expedition to Wyoming in 1878. It is well-timed for our purpose, for it samples the young Edison at the peak of his creative life, in a brief interlude sandwiched between the phonograph (1877) and the incandescent lamp (1879). At the time he worked in the almost magical atmosphere of his first laboratory complex in Menlo Park with a hired staff of twelve loyal assistants: a Camelot where at thirty-one he was both King and Merlin.

. . .

The tasimeter had come to life in a typically Edisonian way: not through any determined effort to discover what was eventually found nor through pure chance or serendipity. Rather he arrived at it through a chain of loosely linked discoveries that led him through several fields, which he was willing to follow hand over hand wherever it took him. He could not always afford this kind of free adventure or the diversion from other specific assignments, but when he found himself upon this course he was at his very best. It was a style of research that fitted Edison well because of his breadth and imagination, his freedom from disciplinary boundaries, and his dogged determination to track down every detail in any of his experiments.

In 1873 Edison was working on schemes to speed up telegraphic transmission in the Atlantic cable. To duplicate in his laboratory the electrical resistance of the 3000-mile cable, he had experimented with a variable resistor made of compressed powdered graphite and had noted the marked electrical sensitivity of powdered carbon to pressure. Four years later, while working on ways of improving Bell's telephone, Edison recalled his Atlantic cable experience and adopted compressed carbon as a telephone transmitter material; thus was born his "carbon button" telephone. There was a problem, however. The hard-rubber telephone mouthpiece was then handheld; heat from the hand transmitted as pressure to the carbon button produced loud static on the telephone line. He first tried to avoid the problem by switching to a cast-iron mouthpiece; this only changed the character of the noise, producing creaky sounds that he attributed to (thermal) motions of iron molecules, which he called “molecular music.”

Edison realized he was being beaten in the telephone game by thermal expansion. Given a lemon he made lemonade. For here was a new device that transformed temperature to resistance: a sensitive heat detector with a readout in the realm of electrical measurement where he was master. It could be made to detect radiant heat by putting the carbon button in mechanical contact with an expandable rod on which heat was focused.He could make it supersensitive by placing the button in one leg of a bridge circuit. To be sure there were a few mechanical details to be worked out and materials to be tried, but the principles were easily in his grasp. This much he knew when he wrote Professor Langley to offer a gift to science. Who cared that it was not at first appreciated? Another of nature's wily signals—this time heat— had wandered into the jaws of one of his traps, and he had it by the hind leg.

To the final instrument Edison added a small conical horn to focus heat and a dial to record compression, presumably for calibration. For the expandable rod he chose vulcanite-the same material that had caused the original problems in the telephone transmitter. The finished instrument was made of machined brass and was small enough to be held in the hand.

Of course, it should also be known that Edison had almost no respect for either education or pure theoretical science in any form:
Edison’s feelings toward the scientists and formal education in general— is better preserved, in opinions he freely gave in later years:

I would’t give a penny for the ordinary college graduate, except those from institutes of technology . . . they aren't filled up with Latin, philosophy, and all that ninny stuff”

His especial disdain was directed at theoretical or mathematical physicists, who seemed to typify dreamy dilettantes in ivory towers. In Edison’s pragmatic mind there was no question as to the relative worth of theoretical vs practical science: “I can hire mathematicians at $15.00 a week, but they can't hire me.”
Soon, I’ll have to get back to my “ninny stuff.”


Plate facing page 256, PHOTOGRAPHY OF TO-DAY by H. Chapman Jones (1923)

But although "pictures" may be made by photographic means, the art of the painter is not readily comparable to the art of the photographer. The photographer does not take a pencil of light and draw with it as the "artist" draws with his pencils, but he so regulates his apparatus that the light itself shall do the drawing. The two cases are fundamentally different. The most important characteristic of photography is that it is so largely automatic. And besides this, if from the present moment all "picture" making means of photography were to cease, photography would still continue to be practiced as one of the most useful of the applied sciences.

It is sometimes argued that it is not necessary to understand the principles upon which photography is founded, because it is sufficient to be provided with a Kodak or other such camera, and to follow the instructions, to get quite acceptable pictures. It is equally true that one only need the barrel organ or musical box and to follow the instructions to get quite acceptable music. And the use of a Kodak gives its possessor less insight into photography than the use of a musical box can into the subject and practice of music, so far as it is possible to compare the two. (17-18)

Sometimes we are met with the question: Can photography lie? And we hear at different times an emphatic yes, and an equally emphatic no, given in reply. Of course photography cannot lie, because all photographic results are due to the effects of the unchanging laws of nature. But a person may be mislead by a photograph, just as he may be mislead by a document, by reason of his won ability to understand it. And a photographer may set himself to produce a deceptive photograph, seeking to gain a dishonest advantage for himself or his customer. But a photograph, so long as it is a photograph and is not sophisticated by hand-painting or other processes, must always have a definite relationship to the thing photographed, according to the conditions under which the photograph was produced. In critical cases it is no more than fair that photographs should be interpreted, when disputes or doubts arise, by those who have studied the subject, just as a legal document is taken to a court of justice when a final opinion is required as to its meaning.

The honest photographer, so far as he is really honest, endeavors to be transparently honest, and to produce work that not only is right, but that appears to be right. This is the aim of all honest persons who have to record facts. But it is astonishing how liable a man who has the very best intentions is to deceive through want of care. And on the other hand, many persons would be surprised if they knew how easily they can be deceived. These are commonplace facts that concern every phase and detail of life, including photography. If the casual observer looks at the illustrations facing page 256, it will seem to him absurd to suggest that the letters L I F E are upright . . .the real fault is in the observer, who does not see the facts as they are. Nevertheless, a photographer who produced a picture that was strictly correct, if it produced a false impression in the minds of a large proportion of those who saw it, would merit blame, because it is the duty of one who records the facts to do his best to demonstrate them also. Indeed, in some matters one might be inclined to allow a little license in fact, if the impression produced is correct, but in photography this is not permissible. The facts should be correctly recorded, fundamentally and absolutely, and a skillful and honest photographer will see that is record is not likely to produce any false idea.

A photograph always records a fact. A thought or an idea may be expressed in various ways, but never by photography. We cannot photograph unless there is a thing to be photographed, and all that a photograph can do is represent that thing. A person may be dressed up to represent Hamlet, and he may be photographed. The photograph is not of Hamlet, but only the person dressed to represent him, and whatever merit there may be in the picture as reminding one of Hamlet, has to do with the person and the dressing and not the photography.

That a photograph always represents facts and nothing else but facts, is its chief characteristic. (264-266)
Photography of Today: A Popular Account of the Origin, Progress, and Latest Discoveries in the Photographer's Art, Told in Non-Technical Language by H. Chapman Jones (1923)


Detail from an E.H. Anthony Instantaneous View, 1860

Our belief is that the American photographers are going ahead of the English and French, as much in the collodion processes as they have in the daguerreotype. Messrs. Anthony's Instantaneous Views are sharp everywhere and free from distortion. Mr. Wilson, after seeing them, says Anthony's pictures are much quicker than mine, and I must get some sort of shutter to open and shut quickly.

Letter quoted in Anthony: An American Photographic Pioneer by William and Estelle Marder
1/2 of a Stereo View of the reception of the Japanese Embassy in New York, 1860, marketed by E.H. Anthony.




Photographed by Infra-Red Light by R.W. Wood

Infra-red light is light of wavelengths too long for the eye to be affected by it—to the eye, therefore, it is not light at all. The usual discrepancy that exists between a view as we see it and as it appears in a photograph when an ordinary plate is used is due to the light being of wave-lengths shorter than those that chiefly affect the eye. This difference is here reversed and very much emphasized. The sky is very dark, the shadows are practically black, and the foliage and grass are so light as to suggest that they might have been covered with snow.
[PHOTOGRAPHY OF TO-DAY by H. Chapman Jones, 1923]

Invisible Rays

This is the oldest example of an infrared photograph I’ve seen. Searching around on the net gives me conflicting information about the date infrared photography developed. One source says that Kodak introduced infrared film in 1922. Another source says that infrared light was discovered in 1903, but that seems unlikely—yet another says that Hershel discovered it in 1800—that seems plausible. I found out a bit more about the energiatype developed by Hunt—he publicized the process in 1844, claiming that it worked with a type of energy as yet undiscovered—which, as it turns out, is ultraviolet light. X-rays were discovered around 1897 I think, so it seems like the nineteenth century was obsessed with invisible rays.

The most interesting stuff I found to-day has more to do with the identity of the photographer who took this picture. He was a famous optician at John Hopkins University, Robert W. Wood. He’s most well known, it seems, for debunking N-rays. One site called him “the P.T. Barnum of physics.” He was known for his practical jokes, but I liked this anecdote the best. It seems that his basement laboratory was filled with cobwebs and cockroaches. He was doing an experiment that involved a long light-baffle that had become covered in cobwebs. He borrowed a friends Persian cat, and a can of tuna. Wood set the open can of tuna at one end of the baffle, and the cat at the other. The cat then walked through the baffle, neatly clearing away the cobwebs.

Wood was also known for another eccentricity. After a rainstorm, he would carry small pellets of sodium wrapped in his pocket. He would spit in the puddles and drop in the sodium pellet at the same time. The resulting small flame convinced everyone that he was spitting fire.




PORTRAIT OF JEANNE SAMARY, BY P. AUGUSTE RENOIR.

Though my partner pretty much has the redhead market sewed-up, I ran across this one and it caught my eye. Reading a little more about Renoir, I was struck by a comment attributed to him in his final phase. After 1890, he was reduced to painting with a brush strapped to his hand from a wheelchair. When asked if that made things more difficult, he said “One does not paint with one’s hands.”




Explosive Photographs

I’ve been reading some papers on early experiments in photography, and the things they tried astound me. Here’s an example:

By very carefully spreading a strong solution of the nitrate of silver over a highly-calendered paper, and then exposing it to the perphosphuretted hydrogen slowly evolved from the phosphuret of lime, a very even metallic surface was formed, from the leaden colour of which it may be concluded some phosphorus had entered into combination with the silver. This paper was soon attacked by the iodine, was little less sensitive than the silvered copper, but it was scarcely possible to remove the iodine, so as to preserve the picture when complete, without portions of the surface breaking away, so slight was the adhesion between the paper and the metal.

By allowing the paper to absorb the silver solution, and to become nearly, but not quite dry before exposed to the gas, and the gas, which I usually form from phosphorus and solution of potassa, being liberated in large quantities, a black paper possessing in a very eminent degree all that is desired, is the result.

Unfortunately, however, although I have used every precaution, I find it impossible to prepare more than a dozen quarter-sheets without an explosion of the gas. In placing and removing the paper, atmospheric air necessarily enters the vessel, besides which, a quantity of oxygen sufficient to occasion spontaneous inflammation is set free from the nitrate of silver and the water absorbed by the papers. On one occasion I so placed and arranged some papers in a vessel as to do away with the possibility of any admission of atmospheric air ; the formation of the black phosphuret of silver was going on beautifully, when the large glass vessel burst with such violence that the largest piece H could find was but the sixteenth of an inch over.

I do not at present see any way of preparing those papers with safety, and, much against any inclination, I have abandoned the use of this gas.
Robert Hunt, “On the Influence of Iodine in Rendering Several Argentine Compounds, Spread on Paper, Sensitive to Light, and on a New Method of Producing, with Greater Distinctness, the Photographic Image,” Philosophical Transactions of the Royal Society of London, Vol. 130 (1840), 325-334.

For the non-chemically inclined, Hunt was treating paper with nitric acid (which can transform the cellulose in the paper to nitrocellulose, or “guncotton”) and then introducing phosphorus and hydrogen gas to the mix. Needless to say, this is an explosive combination on many levels. It made great pictures, evidently—except for the little problem of the photographic paper having a tendency to explode. I’ve been looking for information on a photographic process created by Hunt called the energiotype mentioned by Root in 1864, and listed in an 1880 engineering encyclopedia. This early experiment seems rather energetic in itself.




In a Twinkle

PHOTOGRAPHING A RACEHORSE

The San Francisco Bulletin of June 14 says: “About a year ago E.J. Muybridge succeeded in producing a perfect photograph of Leland Stanford’s trotter, Occident, while moving at full speed. The photograph was the first of a series to show the various motions a trotter’s feet and legs pass through in making one stride in full motion. The interest of that particular photograph was greatly enhanced because it showed the position the horse was in at the moment when his forefoot struck the ground. It completely upset all previous theories concerning the shape of the leg and the part of the foot which first touched the ground. The photograph represents the horse’s foreleg, projecting at considerable of an angle before him, straight as an iron bar, the heel touching the sod and the toe well above the ground. Since then Muybridge has brought electricity to play as an important part in the work of taking the negatives of a fast moving object, and with its aid he has obtained every change in a trotting horse’s position while making a complete stride. A dozen photographs show the various positions of Occident’s body, legs, and feet, while traveling at a 2:24 gait, in a stride of 18 feet 6 inches. The photographs show that a fast trotter’s feet are all off the ground at the same time twice during the making of the stride, although the best accepted authorities on the subject have repeatedly asserted that a trotting horse always has one foot on the ground while in action. These photographs have been taken by Mr. Muybridge at Menlo Park, where apparatus for this special purpose has been erected at a cost of at least $2,000. The camera is exposed and uncovered in a twinkle, by electricity, which is under the complete control of the operator. A board fence on the opposite side of the track has been lined and marked in feet, and a row of cameras are placed to correspond with these, so that the position of the body and limbs is definitely determined. The pictures are a wonderful triumph of photography.”

New York Times, Jun 23, 1878. p. 5

It seems conclusively proved that when you are moving at a higher rate of speed, you leave the ground. No wonder I feel like I have motion sickness lately. There have been too many times lately where I feel that the “twinkle” lasts longer than those moments on the ground. The air feels good, but I can’t utter much more than a gasp in response.








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