Composite portraits and stereoscopic maps.

Galton, Francis, Sir, 1822-1911.

Extract : Memories of my life. Chapter xviii.

New York : E.P. Dutton, 1909.

Description : pages 259-265.

Subject : Composite photography .



Sir Edmund Du Cane and criminal characteristics—Principle of composites—Analytical photography—Stereoscopic photographs of models of mountainous districts

MY first idea of composite portraiture arose through a request by Sir Edmund Du Cane, R.E., then H.M. Inspector of Prisons, to examine the photographs of criminals, in order to discover and to define the types of features, if there be any, that are associated with different kinds of criminality. The popular ideas were known to be very inaccurate, and he thought the subject worthy of scientific study. I gladly offered to do what I could, and he gave me full opportunities of seeing prisons and of studying a large number of photographs of criminals, which were of course to be used confidentially.

At first, for obtaining pictorial averages I combined pairs of portraits with a stereoscope, with more or less success. Then I recollected an often observed effect with magic lanthorns, when two lanthorns converge on the same screen, and while the one is throwing its image, the operator slowly withdraws the light from it and throws it on to the next one. The first image yields slowly to the second, with little sense of discordance in the parts that at all resemble one another. It was obviously possible to photograph superposed images on a screen by the simultaneous use of two or more lanthorns. What was common to all of the images would then appear vigorous, while individual differences would be too faint for notice. There would, however, be great difficulty in accurately superposing them without the aid of expensive apparatus. Then the idea occurred to me that no lanthorns were needed for the purpose, but that the pictures themselves might be severally adjusted in the same place, and be photographed successively on the same plate, allowing a fractional part of the total time of exposure to each portrait.

My earlier experiments were with the full-face photographs of criminals. I selected three which were not greatly unlike, and were of the same size, as judged by measuring the vertical distance between the pupils of the eyes and the parting of the lips. Out of a thin card I cut a window of the size of the portrait, and fastened two threads over it, one vertical, the other crossways. Lastly I made a pin-hole in the card on either side of the window. Thus provided, I laid each portrait in turn on the table, and adjusted the card until the cross line passed over the pupils of the eyes, and the vertical line bisected the interval. Then I pricked through the two pin-holes the paper on which the portrait was. I could thus hang all three portraits one behind the other on two pins that projected from a board, with the assurance that the principal features of each face would occupy an identical position in front of a fixed camera. I photographed them in turns. Th camera was uncapped during one-third of the normal time of exposure while the first portrait was in front of it. Capping it again, I took away the front portrait and exposed the second, then uncapping the camera I took the second portrait ; and similarly the third. The result was particularly promising ; it was difficult to believe that the composite was not a simple portrait. I tested the truth of the result by placing the photographs in different order, and by many other ways. Then I extended its application. The method of composite portraiture was first published in Nature, 1878, and more fully in the Journ. Anthrop. Inst., 1879 [51], also in the Journal of the Photographic Society, at which I exhibited it, and elsewhere. The method is republished in Human Faculty [76].

I gladly acknowledge my indebtedness to Sir Edmund Du Cane not only for helping me with material for these experiments, but for having, as he told me, suggested the inclusion of my fingerprint system in the instructions to the Committee of Identification, described in the last chapter. He was an extremely accomplished man, with high and humane views, and sympathised with not a few of the subjects on which I have been engaged.

I have successfully made many composites both of races and of families. The composites are always more refined and ideal-looking than any one of their components, but I found that persons did not like being mixed up with their brothers and sisters in a common portrait. It seems a curious and rather silly feeling, but there can be no doubt of its existence. I see no other reason why composite portraiture should not be much employed for obtaining family types. Composites might be made of brothers and sisters, parents and grandparents, together with a composite of the race, each in their due proportions, according to the Ancestral Law (see chapter on Heredity). The result would be very instructive, but the difficulty of obtaining the material is now overwhelming. Male and female portraits blend well together, with an epicene result.

With the help of Dr. Mahomed and the permission of the authorities of Guy's Hospital, I took many photographs of consumptive patients and made composites of them, which are published in the Guy's Hospital Reports, vol. xxv. They show two contrasted types, the one fine and attenuated, the other coarse and blunted. Dr. Mahomed was a very promising physician, on the eve of becoming well known, when he caught a fever of the same description, I am told, as that on which he had become an authority, and died of it in his newly purchased house.

I could not make good composites of lunatics ; their features are apt to be so irregular in different ways that it was impossible to blend them. I took a photographer with me to Hanwell, where it was arranged that the patients should sit two at a time on a bench. One of them was to be led forward and posted in front of the camera, while his place on the bench was filled by the second patient moving up into it, whose previous place was to be occupied by a third patient. It happened that the second of the pair who were the first to occupy the bench considered himself to be a very mighty man, I forget whom, but let us say Alexander the Great. He boiled with internal fury at not being given precedence, and when the photographer had his head well under the velvet cloth, with his body bent, in the familiar attitude of photographers while focusing, Alexander the Great slid swiftly to his rear and administered a really good bite to the unprotected hinder end of the poor photographer, whose scared face emerging from under the velvet cloth rises vividly in my memory as I write this. The photographer guarded his rear afterwards by posting himself in a corner of the room.

Many years later, I tried to perform the exact opposite to composite photography, namely, to annul all that was typical in a portrait and to preserve its peculiarities. I called it "Analytical Photography," and explained it in Nature, 1900, and in the Photo. Soc. Jour., 1900-1901. It depends on the fact that a positive and a negative glass plate, both in half or still fainter tones, when held face to face neutralise the peculiarities of one another, so the effect of their combination is to produce a uniform grey. My plan was to fix a negative composite in front of a positive portrait of one of its elements, all in half tones, with the result that the composite abstracted all the typical portion of the portrait while its peculiarities were isolated and remained. "Alice in Wonderland" would have described it as the "grin without the Cheshire Cat." I succeeded, but the result did not give an intelligible idea of the peculiarities, the non- essentials being as strongly marked as the essentials, and the whole making a jumble ; so I went no farther with this process.

In 1882 I published an illustrated memoir in Nature on the conventional way in which artists had hitherto represented a galloping horse. Muybridge had, by means of beautiful photographs of twenty momentary successive attitudes, recently shown, beyond possibility of cavil, that the conventional representation was totally untrue to fact. I asked myself the question why observant artists had agreed for so long a time in drawing galloping horses with their four legs extended simultaneously, and why their representation had never been objected to. It occurred to me that composites of successive attitudes that were too momentary to be distinguished might answer the question, which it did. When all of the twenty attitudes are combined in a single picture, the result is certainly suggestive of the conventional representation, though in a very confused way. Then, finding my own observation that it was difficult to watch all four legs at the same time, also seeing that according to the photographs of Mr. Muybridge, the two fore legs were extended during one quarter of a complete motion, and that during another quarter the two hind legs were similarly extended, I made composites of these groups separately. Then, cutting them in half and uniting the front half of the former to the hind half of the latter, a very fair equivalent was obtained to the conventional attitude. I inferred that the brain ignored one-half of all it saw in the gallop, as too confused to be noticed; that it divided the other half in two parts, each alike in one particular, and combined the two halves into a monstrous whole.

This is a convenient place to speak of the method of stereoscopic maps, which I devised so long ago as 1863. It was published together with specimens made for me by my cousin, long since dead, R. Cameron Galton, in the Proceedings of the Royal Geographical Society [18] of that year. I cannot fully understand why stereoscopes do not hold a higher position in popular estimation than they do ; it may be partly due to two cases—to the fact that the two eyes are unequally operative in a larger proportion of persons than might be supposed, and to the cost and unwieldiness of the usual stereoscope. Compound lenses give better and wider images than plain ones, but for common purposes I find that plain ones, mounted as in an eyeglass, serve quite well enough. Those I generally use are cheap things, mounted in a strip of wood.

I wished to obtain a map that should have the effect of a model, so suitable models were procured and photographed stereoscopically. The result was a perfect success. An unexpected result occurred when a pure white plaster cast was treated in this way, for it wholly failed to give the required appearance of a solid, but if grains of dust were sprinkled over it, much more if names were written on it, the stereoscopic effect appeared in its full strength. Good models, and therefore stereoscopic maps made from them, give a far better idea of a mountainous country than any ordinary map can do, however cleverly it may be shaded. Map-makers might well pay some attention to stereoscopic maps and to providing cheap eyeglasses with which to view them.

51. Composite Portraits, made by combining those of many different persons into a single resultant figure (Anthropol. Inst. Journ., 1879; Nature, 1878; Revue Scientif., 1879).

76. Human Faculty (Macmillan).

18. Stereoscopic Maps, taken from models of mountainous countries (Geogr. Soc. Journ.).

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