This country has, at least until recently, been known for the sort of inventions that change the way people live. Edison’s invention of a usable electric light bulb is one obvious example, and the invention of the transistor in 1948 by the three Bell Labs physicists John Bardeen, Walter Brattain, and William Shockley is another. To this list one could add the invention of Polaroid, the light absorbing material used in sunglasses and wherever else it is desirable to reduce glare, and the invention in 1943 of the idea of “instant” or “one-step” photography. Both of these were the creations of the American-born scientist-inventor Edwin H. Land, now seventy-eight years old. While Land’s Polaroid Corporation is well known to the general public, Land himself has been almost a complete enigma. He has never allowed anyone to interview him at length, never written an autobiography, and never participated in the writing of his biography by anyone else.
On this last matter I consider myself something of an expert. With the encouragement of various mutual friends, some of whom I took to be speaking for Land, I tried for nearly five years to arrange with Land to do a New Yorker profile of him. Since he notoriously does not answer letters, these negotiations, if that is what to call them, were carried on by emissaries, with the exception of an encounter on the evening of November 6, 1982. The Science Museum of Minnesota then celebrated its seventy-fifth anniversary by inviting a small group to join it for the occasion, a group that included Land and myself.
This was my first meeting with Land, and I was immediately taken by what seemed to be his straightforwardness. I was determined not to bring up the subject of the profile, but he almost immediately pulled out his pocket diary to show me my address and telephone number entered in it and he indicated that my request had been much on his mind. In a moment of euphoria I remarked that writing about him would give me an opportunity to learn something about the history of photography, a subject of which I was ignorant. (I did not tell him that I had never owned a camera and knew next to nothing about how one worked.) He looked at me oddly and said, “Photography…photography…that is something I do for a living. My real interest is in color vision.”
I did not have the slightest idea of what to make of this remarkable statement. I did not realize that the previous August he had severed, under not very happy circumstances, his connections with the company he created, and had sold the 15 percent share of stock in Polaroid that he and his family owned. But my first, naive, thought was to compare his situation with those taxi drivers, bartenders, and elevator operators one encounters in New York who say that what they really do is act, sing, or conduct research in cosmology. Evidently color vision, about which I also knew next to nothing, would have to be an important part of the profile. However, I never again heard from Land and my letters to him were never answered.
I mention all of this only to explain how surprising it is to find that there now is a biography of sorts of Land, Land’s Polaroid by Peter C. Wensberg. Mr. Wensberg spent twenty-four years at Polaroid, which he left two months after Land did. His work was largely in advertising and marketing, and when he left Polaroid he was the senior vice-president in charge of marketing. He was the third most important officer in the company after Land and William McCune, the president of Polaroid. As Wensberg makes clear in the prologue, and as Land has said publicly, Land had nothing to do with the book.
Wensberg is candid about his limitations:
Edwin H. Land deserves and requires a scientific biography. His career in science has been a long one, including some achievements that will last well beyond the products of his company. I am not that author and this is not that book.
What then is it?
This is a portrait of a man and a company who occupied the same space, and often, but not always, spoke with the same voice. If it is an admiring portrait, I do not apologize.
To write an admiring portrait of someone one admires—I have done it often—hardly needs an apology, providing one does in fact write a portrait. The trouble with his book is not that it is admiring but that it is not a portrait. The fault seems to be both with Wensberg and with Land. Wensberg was associated with Land for a quarter of a century but does not seem to have a clue about him.
Land is obsessively private, as he has every right to be, but how can anyone claim to have written a “portrait” of him when the first seventeen years of his life—including his family background—are compressed into a single paragraph? We do not even learn if Land had any brothers or sisters. Time magazine’s 1972 cover story about Land contains more information about his early years. The Time reporter had the enterprise to ask Land’s high-school physics teacher what he had been like as a student. The teacher, Raymond Case, reported that in his senior year Land “was already working at a level where I couldn’t help him.”
Wensberg also spends pages on useless digression. There is an entire chapter, for example, on the U-2 spy plane. The only connection I could find to Land was that he was, along with several other prominent scientists, a member of the President’s science advisory committee under Eisenhower, which advised Eisenhower to authorize the spy missions. This Wensberg briefly tells us, after pages of commentary on the plane itself. Wensberg also describes people he neither saw nor heard looking “glumly” at their wristwatches or raising their voices “above the tumult.” Reading these misguided attempts to add verisimilitude to otherwise plausible scenes, one remembers that Wensberg made his career in advertising.
An adequate study of Land would have to include at least three elements. Two of them, the founding of the Polaroid company and the invention of what Land referred to as “one-step” photography, are treated somewhat perfunctorily in Wensberg’s book. The third, his theory of color vision, is not mentioned at all. Yet even a cursory account should make it clear that Land is one of the pivotal figures in creating our technological society; someone whom one might compare to Thomas Edison and certainly to George Eastman, the inventor of the Kodak camera.
Land was born in Bridgeport, Connecticut, in 1909, and entered Harvard in 1926, at the age of seventeen. One cannot get, either from Wensberg’s book or from anything else that I have read, a clear idea of what he was like at seventeen, except that he must have been an unconventional young man. If the various accounts I have heard are to be believed, and I have no reason to doubt them, by his first year in college he had acquired a very specific vocation. The precise circumstances of how this happened are, at least to me, vague, and Wensberg’s book is, alas, only marginally helpful. On a visit to New York while a freshman at Harvard, Land—so the legend, which may even be true, tells us—had a vision. He was walking in Time Square and was troubled by the glare of all the lights, especially the lights of the automobiles and buses. He decided to do something about it—to invent a way of controlling glare.
Given his precocious interest in physics he must have known about the use of polarizers of light to reduce the amount of light transmitted through certain optical media; this is something one would find in a freshman physics text. The study of how wave motions are polarized certainly goes back to the beginnings of the study of wave motion itself. We can imagine the creation of a wave by jiggling a jump rope up and down. When a wave is propagated, the direction of the vibration of the wave is not necessarily the same as the direction of propagation. For sound waves it is, and for light waves it isn’t. In fact for light waves the oscillations of the wave take place at right angles to the direction of propagation, something that physicists refer to as transverse wave propagation. (Sound waves are called longitudinal.) A normal light source produces light with a random mixture of different polarization directions. Our eyes are not sensitive to these different directions of polarization and they absorb light with equal ease whatever its polarization. But some materials are sensitive to it. Crystalline materials such as calcite, for example, absorb light selectively when the direction of its polarization lines up with some axis in the crystal. These materials filter out different directions of polarization, letting through, ideally, only that part of the light beam that has its polarizations lined up just right.
The use of such materials to cut down the transmission of light had been known since the early nineteenth century. Indeed, in 1808, a French physicist named Etienne-Louis Malus discovered that if two such polarizers are put back to back, the amount of light transmitted by the combined system depends on how the polarizers are positioned with respect to each other. In theory the second polarizer, to take an extreme example, would not transmit any light from the first if its axis were at right angles to that of the first. The first substance “polarizes” the light (in Malus’s term) while the second analyzes it. This is the general principle for using polarizers to reduce the transmission of light. But no one had succeeded in making such a material artificially and no one before Land had given much thought to what one would do with such a material if one had it.
I admit that some of Land’s vision in Times Square sounds like a publicist’s dream; perhaps one day Land will tell us if it is true. In any event, Land quit Harvard and moved to New York, at age eighteen, to a basement apartment on West 55th Street, where, apparently supported by his parents, he lived for the next three years and worked on polarization. Why he needed to be in New York as opposed to Cambridge to carry out this work is not clear. Wensberg mentions that the New York Public Library had more books than the Widener Library, but this seems a little hollow as an explanation. In any event Land, it appears, spent his days in the library reading the works of such scientists as the nineteenth-century British chemist William Herapath, who had, in fact, made small artificial crystals that polarized light. Land also found a way to sneak into the Columbia physics laboratories at night, sometimes in the company of his future wife. He also had enough money to hire a technician, Ernest Calabro, who remained with him for the next twenty-five years.
Within three years Land had produced his first artificial polarizing material. The secret was to use microscopic grains of needle-shaped crystals, which polarize light, and embed them in a lacquer. Land called his new product Polaroid glass. It “transmits,” he said, “almost all the useful light rays,” but it contains “a matrix of tiny crystals [that] combs out the tangled waves of light so that they are all vibrating on the same plane. The crystals are so small that you cannot see them. They are suspended in cellulose, all oriented in precisely the same direction.”
Land, now twenty and married, returned to Harvard, where he lasted for another two and a half years. He never took his degree. By this time he had met George Wheelwright III, a physics instructor of independent means six years Land’s senior, who suggested that they open their own laboratory. It became the Land-Wheelwright Laboratories, and in 1934 Land was issued his first patent, for manufacturing sheets of polarizing material. By 1937 the name of the company had been changed to Polaroid and Land had become chairman of the board, president, and director of research. Wheelwright ended up as vice-president. Wensberg does not tell us if this transition was an amiable one. Ironically, in view of a bitter lawsuit that Land and Polaroid eventually won in 1985 for patent infringement by Kodak on the Polaroid instant cameras, the first serious customer of the new company was Kodak, which wanted to use the material as filters for camera lenses.
The immediate future of the company had been secured by its alliance with the American Optical Company, which made sunglasses. Polaroid sunglasses became widely used, and still are. However, as Wensberg reports, by 1940 the market was saturated and Polaroid was reduced to selling its product for use in Wurlitzer jukeboxes, where it enhanced visual effects. No car manufacturer had ever made use of Polaroid in its automobile headlights. In fact, if the war had not come along the Polaroid Corporation might well have gone under. As it was, the company prospered during the war, making a variety of sun goggles for the military and working on the design of heat-seeking missiles.
None of this had anything to do with photography. But in December of 1943 Land had a second inspiration, now also a part of the Polaroid legend. On a rare vacation with his family in New Mexico he spent some time with his daughter Jennifer, then three years old, walking around Santa Fe and taking pictures, with Jennifer directing the picture taking. When they got back to where they were staying Jennifer asked her father about the pictures he had taken: “Why can’t I see them now?”
Our knowledge of the circumstances of this question, and what happened next, comes from Land. Since Wensberg quotes from what appears to be Land’s published account, one has the impression that he never was able to ask Land about it either. This is what Land wrote:
As I walked around that charming town [Santa Fe] I undertook the task of solving the puzzle [Jennifer] had set me. Within the hour, the camera, the film, and the physical chemistry became so clear to me that with a great sense of excitement I hurried over to the place where Donald Brown [Land’s patent attorney, who was conveniently in Santa Fe]…was staying, to describe to him in great detail a dry camera which would give a picture immediately after exposure.
To a Time interviewer Land put things slightly differently. The Time story reads, “He now claims jokingly that by the time he and Jennifer returned from their walk, he had solved all the problems ‘except for the ones that it has taken from 1943 to 1972 to solve.’ ”
In 1972 Land introduced the SX-70, the first color “instant” camera. The best simple explanation I know of how this camera works is given by Land in a talk he delivered in 1956 at the Franklin Institute. It has been reprinted in the Journal of the Franklin Institute under the somewhat ponderous title “From Imbibition to Exhibition.” 1 (At his best Land can be a graceful writer, but writing, one gathers, does not come easily to him, and much of his prose reads that way.) In essence, the idea of one-step photography is to make a sandwich in which a negative and a positive sheet of paper encase an extremely thin layer—0.003 inches in the example Land gave in his 1956 lecture—of a chemical reagent used in developing photographs. The reagent is contained in what Land called a pod. When the pod is run through the camera the pressure on it breaks one end and the fluid runs out between the negative and positive papers.
It is not so difficult to imagine Land having thought up this part of the process. The rest of it is what took genius. In a conventional camera, the film is made up of silver halide, a compound of a halogen, a nonmetallic chemical element, and another element. When enough light falls on one of the grains of this material a speck of silver is produced. If chemical developer is applied, silver ions are induced to migrate through the photographic emulsion, where they deposit themselves on the exposed silver speck. This dark silver represents the exposure to light on the negative. The unexposed grains are then washed away with a solvent (“hypo”), and the result is the photographic negative we have all seen. If this sheet is placed in contact with a light-sensitive sheet—the positive paper on which the photograph is printed—and exposed to light, one soon has the picture. This is the normal two-step process that leads from exposing a negative in a camera to producing a photograph.
Land’s completely novel idea was to have the negative and the positive made at essentially the same instant. This can be done because the reagent in the pod can transport the unexposed silver ions from the negative across the very narrow gap to the positive. In practice the positive is doped with a catalyst that has a chemical affinity for silver. Thus instead of washing away the silver not attached to the negative—the usual procedure—this silver is attached to the positive, creating the positive image essentially simultaneously with the negative image. The dark spots on the negative correspond to the white spots on the positive since the silver that has attached itself to the negative cannot migrate across to the positive. The silver that the negative cannot retain becomes the basis for the image on the positive. In the original versions of Land’s camera, the exposed negative and positive had to be physically separated. There is a famous Life magazine picture of Land, the cover photograph of Wensberg’s book, showing Land looking at a picture of himself which he is revealing by separating the two sheets.
How much of this process Land envisaged that night in 1943 I do not know, but Nobel prizes have been given for less. (To cite two examples: in 1912 Nils Gustaf Dalén was given the Nobel Prize in Physics for a device that automatically regulated lights on lighthouses and buoys; and, more pertinently, in 1908 Gabriel Lippmann was given the Nobel Prize in Physics for his method of reproducing colors photographically.) In November 1948 the first Land camera went on sale for $95 at Jordan Marsh in Boston. It weighed five pounds, took sepia-colored pictures, and was an immediate success. Two years later Land introduced black-and-white film and it was a disaster. The film, once removed from the camera, continued to develop itself until the sharp images simply disappeared. To combat this the positive had to be chemically fixed—by hand painting it—which removed any illusion of the process being “one step.”
Land then made a decision of the kind that seemed characteristic of him. He decided to go for broke and develop an instant color process in which the resulting print would be fixed once and for all. (It remains unclear from Wensberg’s book whether the black-and-white problem was ever really solved.) This effort culminated in 1972 with the introduction of the SX-70, perhaps the most sophisticated invention involving the interaction between camera and film ever achieved. One of the innumerable problems that had to be solved was the battery. Each film pack contains its own battery that runs the automatic focus and the flash lamp. These batteries kept expiring before the film could be used—they still cannot be stored for long without going flat. Polaroid had to develop special batteries.
All of this is described very clearly in Wensberg’s book, as is the marketing of the camera. (Sir Laurence Olivier, chosen to sell the SX-70 on television, was stymied by the pronunciation of “SX,” until he decided it should be “Essex.”) Wensberg is also good on Land’s break with the Polaroid Corporation. He makes it clear that the same obsessiveness that was at work when he quit Harvard at the age of eighteen to go to New York to make a polarizer could be disastrous when his intuition turned out to be wrong.
Land insisted that the SX-70 have a complex viewfinder even though consumer surveys indicated that people didn’t like it. His attitude was that they would have to be educated to like it. He apparently never spoke again to the man who reported the market research to him. Even worse was the disaster of Polavision, a soundless system for taking home movies which was introduced at the time home video was taking hold. By 1977, when the system was introduced, Polaroid had spent millions on it, most of which was lost. By 1982 all of Land’s ties with the company were severed.
Land’s interest in color vision, not discussed at all in Wensberg’s book, goes back at least to the 1960s.2 Like many scientific ideas of great importance Land’s theory starts from a phenomenon we all recognize but do not attach much importance to until someone like Land calls our attention to how remarkable it really is. This is what Land and his collaborators call “color constancy.” It is a fact of common experience that colors retain something like the same appearance, regardless of how the colored object is illuminated. A blue object, for example, looks recognizably blue when viewed from sunrise to sunset. This ability of the brain to maintain the near constancy of colors, even as the illumination is varied, would give a species that had it an evolutionary advantage. An edible red berry, for example, would look like an edible red berry whether encountered at 8 AM or at 5 PM.
Land devised an experiment to exhibit this remarkable fact quantitatively. (He showed a version of it to us in Minnesota in 1982.) It involved boards Land called Mondrians because they resemble the work of that artist. Paper rectangles of different sizes and different colors are pasted on each board. For the sake of illustration we can imagine two adjacent rectangles, one red and one white. According to the scientific theory of color, each color is associated with a specific wavelength of light. When we say that the rectangle or any other object is red, we mean that it will absorb all the wavelengths of light except red ones and reflect back to our eyes only the red wavelength. Hence the object looks red to us. A white object, on the other hand, reflects back all the wavelengths impinging on it, so no color is singled out and the object looks white.
In Land’s experiment the rectangles are illuminated by three colored spotlights—say red, green, and blue. When this is done, the white rectangle reflects all three colors from the spotlights about equally, while the red rectangle absorbs much of the blue and green light and reflects the red. This is what we would expect.
The surprise comes when one begins to change the intensity of the light coming from the different colored spotlights. One can adjust the intensity of the spotlights so that the reflected light coming from the red rectangle has just the mixture of intensities that formerly were reflected from the white rectangle. Naively speaking, one could say the reflected light is now indistinguishable from white light. One might, therefore, be tempted to think that the red rectangle would now look white, just as one might be tempted to think that a red berry viewed at noon would have a different color from that of a red berry viewed at 9 AM. But this is not what happens, either for the berries or, more dramatically, for the Mondrians, where the light intensities can be precisely adjusted. In both cases the red object continues to look red.
This presents a difficult problem for any theory of color. We know that on the outer layer of the retina there are visual cells called “cones.” (There are also “rods,” which have a part in night vision.) Fundamentally there are three types of cones, each one sensitive to wavelengths appropriate to a given primary color. So, for example, approximately a third of the cones respond selectively to red light. (In reality there is some overlap in the sensitivity of the different cones, otherwise we could not see a color like orange, but that is a nuance that need not concern us here.) It would be tempting to say that we see red when our red cones are stimulated by red light and that the more they are stimulated the more red we see. But then how do we explain Land’s experiment in which a red square still looks red even though it reflects, under suitable illumination, the same mixture of light intensities that made a white square look white? The clear implication is that there must be more to color vision than such a naive processing of intensities.
That this is the case was made dramatically clear in a recent article in these pages by Oliver Sacks and Robert Wasserman (The New York Review, November 19, 1987). They describe their study of a painter they call Jonathan I., who lost his sense of color vision when he was injured in a car accident. Elaborate tests showed that his cones were intact. He did not have colorblindness in the usual sense of having defective cones. He was able therefore to register the intensities of different colors when they were presented to him, but he couldn’t see the colors. Still, the images he saw looked different to him when the intensities of the spotlights were changed, whereas a person with normal color vision would have noticed no change.
To see color the brain must therefore be able to do some kind of analysis of visual data beyond simply analyzing the intensities. Land, in collaboration with John J. McCann, has suggested such a model, which they call the “retinex theory.” Basically the idea is that by scanning the entire visual area—not, say, one rectangle but the entire Mondrian—the data processing system responsible for color vision produces three so-called lightnesses, one for short wavelengths, one for medium wavelengths, and one for long wavelengths. It is the combined effect of these lightnesses—a single point in color space, one could say—that determines what color we actually see. A reader who wants to know more about how, according to Land and McCann, the brain calculates the combined effect should consult the references I have given. I am not enough of an expert on the theory of color vision to describe just how Land’s model is to be compared with other models for color constancy. If Land ever writes his autobiography perhaps he will tell us. As I have mentioned, none of this is to be found in Mr. Wensberg’s book. Someday a truly serious biography of Land will be written in which Land’s Polaroid will be a footnote. Or perhaps Land will surprise us all by writing his own book.
April 14, 1988
Journal of the Franklin Institute, Vol. 263, No. 2 (February 1957). ↩
Three accessible references to this matter are: E.H. Land and J.J. McCann, Journal of the Optical Society of America, Vol. 61, No. 1 (January 1971), pp. 1–11; E.H. Land, Scientific American 237, No. 6 (1977), pp. 108–128; and J.J. McCann, “Retinex Theory and Colour Constancy,” in The Oxford Companion to the Mind, Richard L. Gregory, ed. (Oxford University Press, 1987), pp. 684–685. ↩