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Practical Cinematography
and its Applications

BY THE SAME AUTHOR.

Price 6s. net each.

MOVING PICTURES: How they are Made and Worked.

LIGHTSHIPS AND LIGHTHOUSES.

THE STEAMSHIP CONQUEST OF THE WORLD.

THE RAILWAY CONQUEST OF THE WORLD.

LONDON: WILLIAM HEINEMANN.

By permission of the Motograph Co.

How to take Moving-pictures of Wild Animals in Safety.

Messrs. Newman built a huge dummy cow fifteen feet in height of papier-mâché. The operator stands inside with his camera and the pictures are taken through a small hinged door. With this "property" dangerous animals can be approached closely.

Practical Cinematography
and its Applications

By
Frederick A. Talbot
Author of
"Moving Pictures" etc.

London   MCMXIII
William Heinemann

Copyright.

PREFACE

This volume has been written with the express purpose of assisting the amateur—the term is used in its broadest sense as a distinction from the salaried, attached professional worker—who is attracted towards cinematography. It is not a technical treatise, but is written in such a manner as to enable the tyro to grasp the fundamental principles of the art, and the apparatus employed in its many varied applications.

While it is assumed that the reader has practised ordinary snap-shot and still-life work, and thus is familiar with the elements of photography, yet the subject is set forth in such a manner as to enable one who never has attempted photography to take moving-pictures.

At the same time it is hoped that the volume may prove of use to the expert hand, by introducing him to what may be described as the higher branches of the craft. The suggestions and descriptions concerning these applications may prove of value to any who may be tempted to labour in one or other of the various fields mentioned.

In the preparation of this volume I have received valuable assistance from several friends who have been associated intimately with the cinematographic art from its earliest days:—J. Bamberger, Esq., of the Motograph Company, Limited, James Williamson, Esq., of the Williamson Kinematograph Company, Limited, Kodak Limited, Messrs. Jury, Limited, and Monsieur Lucien Bull, the assistant-director of the Marey Institute, to whom I am especially indebted for facilities to visit that unique institution, and the investigation at first hand of its varied work, the loan of the photographs of the many experiments which have been, and still are being, conducted at the French "Cradle of Cinematography," and considerable assistance in the preparation of the text.

Frederick A. Talbot.

CONTENTS

CHAP.

 

PAGE

I.

ATTRACTIONS AND OPPORTUNITIES OF THE ART

1

II.

THE PRINCIPLES OF CINEMATOGRAPHY

13

III.

THE MOVING-PICTURE CAMERA AND ITS MECHANISM

21

IV.

CAMERA AND HOW TO USE IT

35

V.

HAND CAMERA CINEMATOGRAPHY

51

VI.

DEVELOPING THE FILM

62

VII.

PRINTING THE POSITIVE

79

VIII.

ABERRATIONS OF ANIMATED PHOTOGRAPHY

94

IX.

SLOWING-DOWN RAPID MOVEMENTS

108

X.

SPEEDING-UP SLOW MOVEMENTS

124

XI.

CONTINUOUS CINEMATOGRAPHIC RECORDS

135

XII.

RADIO-CINEMATOGRAPHY: HOW THE X-RAYS ARE USED IN CONJUNCTION WITH THE MOVING-PICTURE CAMERA

147

XIII.

COMBINING THE MICROSCOPE AND THE ULTRA-MICROSCOPE WITH THE MOVING-PICTURE CAMERA

161

XIV.

MICRO-MOTION STUDY: HOW INCREASED WORKSHOP EFFICIENCY IS OBTAINABLE WITH MOVING-PICTURES

174

XV.

THE MOTION PICTURE AS AN AID TO SCIENTIFIC INVESTIGATION

185

XVI.

THE MILITARY VALUE OF THE CINEMATOGRAPH

197

XVII.

THE PREPARATION OF EDUCATIONAL FILMS

209

XVIII.

PHOTO-PLAYS AND HOW TO WRITE THEM

224

XIX.

RECENT DEVELOPMENTS IN STAGE PRODUCTIONS

238

XX.

WHY NOT NATIONAL CINEMATOGRAPH LABORATORIES?

248        

INDEX

259

LIST OF ILLUSTRATIONS

 

FACING

PAGE

How to take Moving-pictures of Wild Animals in safety

Frontispiece

A Moving-picture Expedition into the Indian Jungle

4

Polar Bear Diving

5

A Lion and Lioness at Lunch

10

Caught!

11

Operator and Camera buried in a Hole

14

Making Moving-pictures of Wild Rabbits

14

Nest of King Regulus, showing curious Suspension

15

Mother King Regulus feeding her Young

15

The Jury Moving-picture Camera

24

The Williamson Topical Camera and Tripod

25

The Williamson Camera threaded for Use

42

Lens of the Williamson Camera

43

Adjustable Shutter of the Jury Camera

43

The "Aeroscope" Moving-picture Hand Camera

52

Compressed Air Reservoirs of the "Aeroscope" Camera

53

Lens, Shutter, Mechanism and Gyroscope

56

Loading the "Aeroscope" Camera

57

Mr. Cherry Kearton steadying himself upon a Precipice

58

Mr. Cherry Kearton slung over a Cliff

58

Vulture preparing to Fly

59

A Well-equipped Dark Room showing Arrangement of the Trays

64

Winding the Developing Frame

65

Film transferred from Developing Frame to Drying Drum

72

Film Wound on Frame and placed in Developing Tray

73

The Jury Combined Camera and Printer

73

The Williamson Printer

84

Water Beetle attacking a Worm

85

Marey's Apparatus for taking Rapid Movements

112

Cinematographing the Beat of a Pigeon's Wing

113

First Marey Apparatus for Cinematographing the Opening of a Flower

128

First Motion Pictures of an Opening Flower

129

Development of a Colony of Marine Organisms

129

Continuous Moving-picture Records of Heart-beats

136

Continuous Moving-pictures of Heart-beats of an Excited Person

137

Continuous Cinematography—Palpitations of a Rabbit's Heart

142

Stero-motion Orbit of a Machinist's Hand

143

Lines of Light indicating to-and-fro hand Movements

143

A wonderful X-ray Film made by M. J. Carvallo

148

Moving X-ray Pictures of the Digestion of a Fowl

149

Stomach and Intestine of a Trout

152

Digestive Organs of the Frog

152

Lizard Digesting its Food

152

X-ray Moving-pictures of the Bending of the Knee

153

X-ray Film of the Opening of the Hand

153

Micro-Cinematograph used at Marey Institute for investigating minute Aquatic Life

164

Micro-cinematography: The Proboscis of the Blow Fly

165

Micro-cinematograph used at the Marey Institute

170

One of Dr. Comandon's Galvanic Experiments with Paramoecia

171

Micro-cinematography: Blow Fly eating Honey

176

The Ingenious Gilbreth Clock

177

Rack, showing Disposition of Component Parts, for Test

177

Film of Workman assembling Machine

182

Film of Rack and Bench, Floor marked off into Squares, and Clock

182

Cinematographing a Man's Work against Time

183

Moving-pictures of a Steam Hammer Ram

188

Dr. Füch's Apparatus for taking Moving-pictures of the Operations of a Steam Hammer

189

Wonderful Apparatus devised by Mr. Lucien Bull for taking 2,000 Pictures per second

190

Moving-pictures of the Ejection of a Cartridge from an Automatic Pistol

191

Motion Photographs of the Splintering of a Bone by a Bullet

191

Soldiers Firing at the "Life Target"

204

Front View of the "Life Target" showing Screen Opening

205

Screen Mechanism of the "Life Target"

206

Cinematographing Hedge-row Life under Difficulties

207

Moorhen Sitting on her Nest

212

The Young Chick pierces the Shell

212

Chick Emerging from the Shell

213

Newly Hatched Chick struggling to its Feet

213

Chick, Exhausted by its Struggles, Rests in the Sun

214

The Chick takes to the Water

214

Fight between a Lobster and an Octopus

215

Story of the Water Snail

215

The Head of the Tortoise

218

The Hawk Moth

218

Snake Shedding its Skin or "Slough"

219

The Snake and its Shed Slough

219

Exterior View of Dummy Cow

226

Mr. Frank Newman and Camera hidden within Tree Trunk

227

Lizard with Spider in its Mouth

240

Digestive Organs and Eggs of a Water Flea

241

Moving-picture Naturalist and the Lizard at Home

241

A Novel "Hide," with Camera Fifteen Feet above Ground

250

"Hide" Uncovered showing Working Platform

251

IN TEXT

FIG.

 

PAGE

1.

Mechanism of Camera showing Threading of Film

28

2.

The "Pin" Frame

67

3.

The First Picture of the Four-spoke Wheel

97

4.

Apparent Stillness of Spokes while Wheel is Moving

98

5.

Apparent Backward Motion of Spokes while Wheel is Running Forwards

99

6.

When Wheel is seen to be Moving Naturally

100

7.

Curious Illusion of seeing Twice the Number of Spokes in the Wheel

102

8.

Mechanism of the Noguès Camera

115

9.

The Ingenious Radio-cinematographic Apparatus devised by Monsieur M. J. Carvallo

151

10.

Dr. Comandon's Radio-cinematographic Apparatus

157

PRACTICAL CINEMATOGRAPHY

CHAPTER I
ATTRACTIONS AND OPPORTUNITIES OF THE ART

Profit and pleasure combine to win recruits for the art of animated photography. As an entertainment offered to the public, the moving-pictures have had no rival. Their popularity has been remarkable and universal. It increases daily, and, since we are only now beginning to see the magnitude of what the cinematograph can effect, it is not likely to diminish. This development has stirred the ambition of the amateur or independent photographer because the field is so vast, fertile, and promising. Remunerative reward is obtainable practically in every phase of endeavour so long as the elements of novelty or originality are manifest. The result is that it is attracting one and all. Animated photography can convey so fascinating and convincing a record of scenes and events that many persons—sportsmen, explorers, and travellers—make use of it.

From the commercial point of view the issue is one of magnetic importance. In all quarters there is an increasing demand for films of prominent topical interest, either of general or local significance. The proprietors of picture palaces have discovered that no films draw better audiences than these. If they deal with a prominent incident like a visit of royalty to the neighbourhood, an important sporting event, a public ceremony, or even, such is human nature, with some disaster to life or property, they will make a stronger appeal for a few days than the general film fare offered at the theatre, because the episode which is uppermost in the mind of the public is what draws and compels public attention. Even, it would seem, when the reality itself has just been witnessed by the audience, its photographic reproduction proves more attractive than all else.

The picture palace, indeed, is assuming the functions of the illustrated newspaper, and is governed by like laws. The more personal and immediate the news, the more pleased are the beholders. So there is an increasing effort to supply upon the screen in life and motion what the papers are recording in print and illustration. One can almost hear the phrase that will soon become general, "Animated news of the moment." Already the French are showing us the way. In Paris one is able to visit a picture palace for 25 centimes at any time between noon and midnight and see, upon the screen, the events of the hour in photographic action. As fresh items of news, or, rather, fresh sections of film, are received, they are thrown upon the screen in the pictorial equivalent of the paragraphs in the stop press column of the newspapers, earlier items of less interest being condensed or expunged in the true journalistic manner to allow the latest photographic intelligence to be given in a length consistent with its importance.

It is obvious that this branch of the business must fall largely into the hands of the unattached or independent worker, who bears the same relation to the picture palace as the outside correspondent to the newspaper. A firm engaged in supplying topical films cannot hope to succeed without amateur assistance. No matter how carefully and widely it distributes its salaried photographers, numberless events of interest are constantly happening—shipwrecks, accidents, fires, sensational discoveries, movements of prominent persons, and the like, at places beyond the reach of the retained cinematographer. For film intelligence of these incidents the firm must rely upon the independent worker.

Curiously enough, in many cases, the amateur not only executes his work better than his salaried rival, but often outclasses him in the very important respect that he is more enterprising. Acting on his own responsibility, he knows that by smartness alone can he make way against professionals. Only by being the first to seize a chance can he find a market for his wares. Thus when Blériot crossed the English Channel in his aeroplane it was the camera of an amateur that caught the record of his flight for the picture palaces, although a corps of professionals was on the spot for the purpose. True, the successful film showed many defects. But defects matter little compared with the importance of getting the picture first or exclusively. Similar cases exist in plenty. The amateur has an excellent chance against the professional. His remuneration, too, is on a generous scale. The market is so wide and the competition is so keen, especially in London, which is the world's centre of the cinematograph industry, that the possessor of a unique film can dictate his own terms and secure returns often twenty times as great as the prime cost of the film he has used.

By permission of the Motograph Co.

A Moving-picture Expedition into the Indian Jungle.

Mr. Cherry Kearton, the famous cinematographer of wild animals, and his outfit loaded upon an elephant.

By permission of the Motograph Co.

Polar Bear Diving. A Striking Motion-picture

The market is open also to travellers, explorers, and sportsmen. These, with a cinematograph camera and a few thousand feet of film, can recompense themselves so well that the entire cost of an expedition may be defrayed. An Austrian sportsman who roamed and hunted in the North Polar ice fields received over £6,000 ($30,000) for the films he brought back with him. Mr. Cherry Kearton, who took pictures of wild life in various parts of the world, sold his negatives for £10,000 or $50,000.

Scientific investigators are in the same happy case. When their researches lead them to anything that has an element of popular appeal, there is profit awaiting them at the picture palace. The life of the ant, for instance, or electrical experiments, or interesting phases of chemistry, and many other features of organic and inorganic science, yield good returns to the scientist with a camera. Such films will command 20s. ($5) or more per foot of negative.

There is another branch of the work already well established. The producer of picture plays, if his plot be tolerably good and the scenes well acted and well photographed, and if the play itself promises some popular success, can command a good price. At the moment there are several independent producers at work throughout the world. They have a large open market for the disposal of their wares and find no difficulty whatever in selling all they can produce. Even the largest producers, who have huge theatres and command the services of expert scenario writers and players, do not hesitate to purchase from outside sources.

A cinematograph camera, and a little luck, will make anyone's holiday profitable. The travelling amateur penetrates into places overlooked by the professional, and usually takes greater pains with his work. Afterwards he finds his market in the fact that the demand for travel pictures is so great that a good film of 300 feet will fetch £40 ($200) and upwards. At home he may exploit his ingenuity in making trick films, a most popular feature at the picture palaces, so long as he keeps novelty to the forefront. Trick films, unfortunately, take so long to prepare and demand such care, skill and patience that the largest firms of producers as a rule are not eager to attempt them, because their production disorganises the more regular and profitable work of the studio. A good trick film of 800 feet may occupy six months in preparation. But the amateur may approach what the large firm fears. To him time is no object, and he is able to maintain his interest, care, and ingenuity to the end of the quest. On the other hand the professional worker often tires of his trick subject before the task is half completed, with the result that novelty and care are not sustained. One industrious Frenchman devoted nearly a year to the preparation of a film in which resort had to be made to every conceivable form of trickery, and sold his product for £3,000 or $15,000. He also refused an offer of £5,000 ($25,000) for another film of pictures calculated to please children.

To sum up, the amateur or independent cinematographer has a vast field available for the profitable exercise of his skill. Except in regard to the topical work, which is of the rush-and-hustle order, he must show imagination in his choice of subject and craftsmanship in the execution of his work. He must, that is to say, be trained so far as to be no longer an amateur in the popular meaning of the word. He must learn aptitude in the school of experience. The reward is well worth the trouble.

Hitherto the amateur worker has been held back by the great expense of the necessary apparatus. The camera cost £50 ($250), and the developing and printing operations were generally supposed to be too difficult and costly for private undertaking. There was some excuse for these notions. The trade at first followed narrow lines, no welcome being held out to the amateur competitor. But circumstances have been too strong for this trade, as for others, and it burst its bonds in due time. The co-operation of the independent worker became essential as the demands of the market increased. In the production of plays, for instance, England at first led the way. But the American and French producers came quickly to the fore. The English pioneers, not being skilled in the mysteries of stage craft, wisely retired from the producing field upon the entrance of the expert from the legitimate theatre, who realised that the moving-picture field offered him increased opportunities for his knowledge and activity as well as bringing him more profitable financial returns for his labours. The British fathers of the industry devoted their energies to the manufacture of cinematographic apparatus, as they foresaw that sooner or later the amateur and independent worker must enter the industry. The activity of amateurs was needed by the English trade as a whole, and the manufacturer, with great enterprise, brought down the cost of apparatus to a very reasonable level. This has been effected by methods not less advantageous to the purchaser than is the reduction of the price—by standardisation of parts and simplification of mechanism.

To-day a reliable camera for living pictures, suitable for topical and other light work, can be bought for £5 or $25. A more expensive camera, the Williamson, costs £10 10s. ($52), and is actually as good as other machines priced at four or five times that sum. On the other hand, so much as £150 ($750) can be paid. But the camera sold for this large sum demands a purchaser with something more than a long purse. It demands special knowledge. Designed for studio work, it has peculiarities that are difficult to master and is not to be recommended to a beginner.

With the cost of the camera the cost of other apparatus has fallen in proportion. It was realised that the amateur's dark room and other facilities are likely to be less excellent than those of the professional and that he must be provided with compensating conveniences. This problem has been solved. A complete developing outfit can now be packed in a hand-bag, and a camera and printing outfit can be carried in a knapsack no larger than is required for the whole-plate camera of the old "still-life" photographer. Simple and efficient appliances for the dark room can be purchased very cheaply. There is a portable outfit for use in field work, where it is imperative that films should be developed as soon as possible after exposure, and this outfit is now used by the majority of travellers and field workers, such as Cherry Kearton, Paul Rainey, and others. Distinct advantage, it may be observed, comes from prompt developing. There may be vexatious delay, occasionally, but the photographer is at least able to tell quickly whether his film is a success or a failure. It is better to gain this knowledge on the spot, even compulsorily, where another record can be taken, than to gain it later a few hundreds of miles from the chance of trying again.

The capital expenditure of the cinematographer need certainly not be great. A complete outfit, the "Jury," may now be obtained for £20 or $100. It comprises a combined camera and printer, developing troughs, film-winding frames for developing and drying, and all necessary chemicals. Yet it is no toy, as might be thought, but a thoroughly reliable outfit capable of doing first-class work. Anyone who is more ambitious, or willing to spend more money, should purchase the Williamson outfit. This costs about £40, or $200.

Now for other difficulties that have nothing to do with money. It has been assumed that the art of animated photography is a mystery demanding a long and weary apprenticeship. But the impression is really quite wrong. Anyone who has practised still-life and snap-shot photography may become proficient in the new art within a week or two. Many of the problems encountered in the old photography are actually easier to solve in the new; some are eliminated entirely; others, that are intensified, are really not very hard to master.

From the "Cinema College," by permission of the Motograph Co.

A Lion and Lioness at Lunch.

By permission of the Motograph Co.

Caught!

A jungle-fowl brought down by a leopard.

Animated photography is nothing more than a Kodak worked by machinery. Instead of the shutter being actuated by hand to make an exposure, and the film afterwards moved by turning a roller so as to bring a fresh area before the lens, the two movements, in the cinematograph, are combined. The rotation of the handle alternately opens and closes the lens, and moves the film forward a defined distance after each exposure. Therefore, speaking generally, if the beginner knows how to use an ordinary camera and is familiar with subsequent operations of developing and printing, he should be able to accustom himself quite readily, with little waste of material, to the different conditions of motion photography.

There is practically but one process that he should not at first attempt. This is the perforation of the film. The film is a celluloid ribbon and is punctured near either edge, at intervals, so as to enable it to be gripped by the claws of the mechanism and moved forward intermittently a definite distance—three quarters of an inch—through the camera. This puncturing or perforation of the film is the most delicate of the whole cycle of operations. It can only be done by a machine of unerring precision manipulated with extreme care. The machines, though many are on the market, are somewhat expensive, and it is upon them that the steadiness of the picture on the screen depends. The inaccuracy in the perforation may be slight, a minute fraction of an inch, but it must be remembered that each picture on the film is magnified more than fifteen thousand times upon the screen, and the errors are magnified in proportion. But these considerations need not trouble the amateur. He can purchase his "stock," as the unexposed film is called, perforated ready for use.

In spite of the great reduction in the cost of both camera and outfit the expense of cinematography is still its drawback. The film is the culprit. It costs from 2d. to 4d.—say, from 4 to 10 cents—a foot. Yet in this case, as in others, reduction seems to be within sight. The increased demand is sure to cheapen the process of production. If the price is not then lowered as much as could be hoped the cause will be in the cost of the basic materials. These also, perhaps, will become less dear in time. Cinematography is an industry in revolution. Its possibilities are only beginning to be seen; its followers are only beginning to be counted; but it can hardly be doubted that the ranks of the amateur and independent workers are certain to increase considerably and rapidly. The attractions and inducements to practise the craft are too alluring to be ignored.

Contents

Index

CHAPTER II
THE PRINCIPLES OF CINEMATOGRAPHY

For complete success in moving-picture work it is essential to have an elementary knowledge of the principles upon which the art is based. Although pictures are said to be shown in motion upon the screen, no action is reproduced as a matter of fact. The eye imagines that it sees movement. Each picture is an isolated snap-shot taken in the fraction of a second. In projection upon the screen, however, the images follow so rapidly one after the other and each remains in sight for so brief a period that the successive views dissolve into one another. The missing parts of the motion—the parts lost while the lens is closed between the taking of each two pictures—are not detected by the eye. The latter imagines that it sees the whole of the process of displacement in the moving objects. In fact it sees only one-half—the half that occurred in those fractions of seconds during which the lens was open. What occurred while the lens was shut is not recorded. Animated photography, therefore, is an optical illusion purely and simply.

The fact that an appearance of natural movement is seen under these conditions is due to a physiological phenomenon which, for the want of a better explanation, is termed "persistence of vision." This peculiarity of the eye and brain remains a scientific puzzle, and although in one or two quarters the theory of visual persistence is ridiculed, the iconoclasts have not yet brought conclusive testimony to upset it. The whole subject of persistence of vision in its relation to moving-pictures is discussed at length by the present writer in a former book to which he would refer such readers as may wish for information on this subject.[1]

Operator and his Camera buried in a Hole to take Moving-pictures of Small Animals.

By permission of the Motograph Co.

Making Moving-pictures of Wild Rabbits.

Mr. Frank Newman with his camera concealed in the bushes.

From the "Cinema College," by permission of the Motograph Co.

The Nest, showing Curious Suspension By Four Strings.

A Unique Picture. The Mother King Regulus Feeding her Young.

Motion-pictures of the Golden-crested Wren, the smallest bird in the British Isles.

The eye is about one million times faster than the most rapid sensitized emulsion which chemists have yet produced. So there is nothing wrong about the popular opinion that the organ of sight is the quickest of the senses. Yet it is not so quick that it cannot be deceived. If the pictures of a cinematograph are projected upon the screen at the rate of so many per second, the effect upon the eye is that of perfectly natural movement. The laws that govern this illusion have been discovered in a very interesting way. A positive film was prepared, but between each successive image a wide white line was inscribed. This film was then passed through the projector, and the pictures were thrown upon the screen at the speed generally accepted as being necessary to convey the effect of natural movement; but animation could not be produced at all, however rapidly the pictures were projected. The reason was simple. Immediately after a picture disappeared from the screen the white flash occurred, and notwithstanding its instantaneous character it was sufficient to wipe out the image of the picture, which without the white line would have lingered in the brain. Even when the pictures were run through the projector at thirty per second, no impression of rhythmic movement was obtained; they appeared in the form of still-life pictures with spasmodic jumps from one to the other. They failed to blend or dissolve in the brain, notwithstanding that the white flash in some cases was only about one ten thousandth part of a second in duration.

Another film of the same subject then was passed through the projector under conditions exactly similar except that the line dividing the pictures in this case was black instead of white. When this picture was thrown upon the screen, animation became apparent directly the speed attained sixteen pictures per second, because after one image had vanished from the screen it persisted in the brain, in spite of the black flash, until the next picture appeared. Thus, the requisite dissolving effect was obtained. The black flash did indeed produce a defect like that which was common in the early days of cinematography and was characterised generally as "flicker." But it did not suffice to ruin the illusion of movement. A white flash destroys apparent motion, owing to the brain being extremely sensitive to white: a black flash of equal duration exercises no ill effects.

In the latest development of the art, one inventor has taken advantage of this peculiarity. He has perfected a practical system wherewith the shutter of the camera may be abandoned because each picture is cut off from its neighbour by a very thin black line. An improved mechanism jerks each picture off and brings the next one on the screen very sharply, so that an effect is produced like that obtainable with the shutter and without any impression of flicker. It may be pointed out that with this invention there are none of the aberrations described in a later chapter, such as the spokes of a wheel appearing to move in the reverse direction to which the rim is travelling.

The next question is that of the speed at which it is necessary to take and to project the pictures in order to get an apparently true impression of natural movement. This factor to-day is governed almost entirely by commercial considerations. It has been found, as a result of elaborate investigation, that a speed of twelve to sixteen pictures per second is the minimum wherewith in monochrome pictures animation is obtainable. But this applies only to general work, such as records of ordinary scenes, topical events and stage plays, where the action of the moving objects is comparatively slow. In these instances an average of sixteen pictures per second in photographing and projecting gives completely satisfactory effects.

But in reality the speed is a variable quantity: it must be adapted to the subject and the character of the work in hand. In other words, strictly speaking, the speed must be accommodated to the velocity of the subject so far as photographing is concerned, and also, in a lesser degree, to the distance of the moving object from the lens. For instance, when a man, walking four miles an hour, is photographed at sixteen pictures per second, the movements recorded are far from being natural or rhythmic. On the screen he appears to walk with a disjointed action. To obtain a lifelike result, his pace should be slowed down 75 per cent., or the photographing speed should be accelerated to seventy pictures per second at the least. This fact is illustrated very conclusively in pictures of soldiers marching: they appear to advance like automatons. Again, in photographing animals, a complete movement is often lost between successive pictures. A cat in one picture will be seen to the right; in the next picture it is on the left, having sprung from one side to the other during the brief interval the lens was closed. When extremely rapid movements have to be recorded, the photographing speed has to be accelerated to an extreme degree, up to ten thousand pictures or more per second in the case of a bullet leaving the muzzle of a rifle, and up to two thousand pictures per second to catch the movements of a dragonfly's wings. On the other hand, in photographing very slow movements like the growth of a plant, one picture per hour may be adequate.

In projection the speed can be adjusted. The ten thousand pictures per second may be decelerated to sixteen per second to allow the movement to be followed, and although the rifle bullet may appear to crawl through the air, the movement is perfectly correct. Similarly the very slow motions must be accelerated to sixteen pictures per second to obtain evident animation. These two extreme phases of cinematographic investigation are described at length in another part of this volume, but are mentioned here merely to show that the photographing speed is a somewhat elastic factor, to be adapted to circumstances in order to produce passably natural effects.

For everyday work, however, a speed of sixteen pictures per second is sufficient and represents the generally practised velocity. Possibly in the near future the speed will be accelerated to twenty, twenty-two, or twenty-four pictures per second, as the present speed is generally admitted to be too slow. The eyes of the regular picture palace patrons have become trained, as it were, with the result that there is an appreciable strain of the eyes, while the disjointed character of the movements on the screen may be detected. But when the taking and projecting speed is accelerated by 50 per cent. the picture stands steadier upon the screen, the movements are more natural, and there is an entire absence of that automaton effect which is so characteristic of most pictures taken under prevailing conditions. These considerations do not affect photo-plays produced in the studio so materially, because there the actions of the players can be slowed down to suit the conditions.

One of the leading manufacturers is earnestly considering the advisability of accelerating the taking and projecting speeds up to about twenty pictures per second, and private investigations and experiments have certainly demonstrated the value of such an improvement. Unfortunately two difficulties prevent its immediate realisation. An increase of only four pictures per second represents an increase of 25 per cent. in the consumption of the film, and therefore in its cost. The other difficulty is more serious. Existing apparatus, both cameras and projectors, are geared to eight pictures per turn of the handle. This involves two complete revolutions per second. Consequently the gearing of the mechanism would have to be altered, and this is a more troublesome question than appears at first sight. Some time may elapse before a forward step is taken in this direction. In matters of this character the cinematograph industry is notoriously conservative, although the moment one firm courageously adopts an accelerated speed, the higher quality of the resulting pictures will force the others to follow the example.

As a matter of fact the decision to adopt sixteen pictures per second was taken somewhat haphazardly without any scientific investigation. When it became standardised, film was expensive. Accordingly, efforts were made to secure the requisite effect with the minimum expenditure of film. Machines were built to coincide with these requirements, and the original designs have been followed slavishly in their broad outlines ever since.

Contents

Index

CHAPTER III
THE MOVING-PICTURE CAMERA AND ITS MECHANISM

The cinematograph camera differs entirely from the instruments used in other branches of photography. While the advanced worker and the prosperous picture-play producer employ costly and elaborate machines, the amateur, or the independent worker, in the particular field which he has selected for his operations, can get equally good results with an apparatus only a fifteenth or even a twentieth part as expensive. The range of operation with the cheaper instrument may be limited, and it may be deficient in those many little refinements which are characteristic of the professional appliance, and may lack silver-plated finish and highly-polished woodwork or morocco leather covering. But the camera itself is more important than these.

The cameras, both expensive and low-priced, work upon the same fundamental principles. In the latter everything is reduced to the simplest form so as to be readily and easily understood by the beginner. They have the additional recommendation that the risk of breakdown is eliminated, because the few essential component parts are substantially made, well-proportioned, and nicely-balanced. Serviceability and reliability are the outstanding features of the low-priced camera, and it is applicable to almost every branch of the craft.

Contrary to general belief, taking the "movies" is quite as simple as snap-shot photography with a Kodak. In the latter case you press the button; in the former you turn the handle; the camera does the rest. The rotation of the handle, a simple operation, performs every duty through the internal mechanism. It swings the shutter across the lens, moves the film intermittently through the instrument, and coils up the exposed film in its dark box.

As has been explained, the beginner is now able to make his selection from a wide variety of makes, ranging in price from £5 ($25) upwards. If one desires to gain experience in the cinematographic art with the minimum capital outlay, the Jury, "New Era," or "Alpha" cameras will suit the purpose excellently. Both are first-class, well-made machines, having perfect registration and alignment, extremely simple and easy to handle. The first-named model, which is the cheapest, is contained in a mahogany case measuring 9½ inches square by 4¾ inches deep, and in the unloaded condition weighs 5½ pounds. The "Alpha," which costs a little more, is full value for money, and is well worth the slightly increased price. This camera is fitted with a light-proof hinged front panel giving access to the adjustable shutter, which permits the opening of the latter to be varied within wide limits and thus enables extremely rapid movements to be photographed while running the machine at the normal speed. The spool boxes carry 100 feet of film of standard gauge in each instance, and for general all-round work, such as the recording of topical events, either model will be found perfectly efficient. It may be mentioned that both models are supplied without the lens, because the average beginner in motion-picture work, having practised still-life or snap-shot photography, has usually developed a marked fancy for some particular make of lens—Dallmeyer, Cooke, Ross, Zeiss-Tessar, or Voigtlander. Naturally, being familiar with the working of his favourite and knowing what he can do with it, he feels more at home when he is able to have it fitted to his moving-picture machine. Here, again, there is a wide selection to meet all purses, so that the most fastidious tastes in regard to the lens may be gratified. On the other hand, if the beginner has no marked preference, and wishes to be economical, he can get a lens capable of doing first-class work at a remarkably low price. His complete outlay upon the camera and the lens need not exceed £6 5s., or, say, $31.

If prices are not to be so strictly considered, and if the beginner wishes to have a machine of the finest type at a comparatively low figure, he cannot do better than fit himself out with a Williamson camera, the price of which, complete with lens, is £10 10s., say $52. Except for an expert, it is difficult to detect the difference between this machine and one which costs five times as much, for both are designed upon the same lines, are equally well made, and equally capable of doing the finest work. It must not be forgotten that Mr. James Williamson, the designer of the latter instrument, was one of the pioneers in cinematography, and, in his machine, the results of some twenty-five years varied and accumulated experience are incorporated. He has been able to realise just those essentials which are required for a high-class apparatus free from complexity, and this end has been achieved to excellent effect. The camera, finished in a brass-bound mahogany or teak case—the latter is preferable for working in tropical countries—measures 9½ inches square by 4¾ inches deep, is fitted with a Zeiss-Tessar 2-inch lens with focusing, and iris diaphragm. It weighs 7½ pounds complete in loaded condition. It is eminently suited for all round duties, from the rush and tumble of topical work to the uneventful, quiet but exacting requirements of the laboratory.

The Jury Moving-picture Camera.

B. Driving sprocket. A, C. Upper sprocket pulleys. D. Exposure window. H. Gate. E, F. Lower sprocket pulleys. G. Exposed film-box guide pulley.

The Williamson Topical Camera and Tripod

A. Camera. B. Handle. C. Lens. D. View finder. E. Tripod head. F. Horizontal panoramic movement handle. G. Vertical panoramic movement handle.

These machines by no means exhaust the selection. Other manufacturers have produced very good instruments at competitive prices, but those which I have mentioned represent probably the best in their respective classes. For the purpose of introduction to the art of cinematography the beginner can do no better than obtain one of them. If, after a little experience, he comes to the conclusion that he has ventured into the wrong province, then his monetary expenditure is not serious.

It will be seen that the aspirant has no lack of inducement to embark upon the moving-picture industry. Provided he has acquired a certain knowledge of the elements of photography, and is possessed of average intelligence, there is no reason why he should not be able to produce pictures with his inexpensive machine that are in all ways comparable with the product of the professional worker and the costly instrument. Naturally, as the intricacies of the craft are mastered, the tyro will wish for a more elaborate apparatus. He can gratify his ambitions in accordance with his progress, or with the improvement in his financial position.

The mechanism of the modern cinematograph camera is very simple in its character and very easy to understand. The necessary parts are very few in number. In all cameras the chief object is to effect the forward intermittent movement of the film at regular intervals and for a defined distance. For this purpose the early types of camera were fitted with what is known as the Geneva stop movement. Opinion is divided upon its merits, some authorities condemning it unequivocally, while others uphold it strenuously, contending that it gives a steadier and freer motion. There is much to be said in favour of the latter view. Mechanically the Geneva stop movement is perfect. So far as cinematography is concerned its advantages were proved most emphatically by Mr. Robert Paul, the first man to bring motion pictures into commercial application in Great Britain. He adopted this movement in his camera, and it cannot be denied that his pictures were in every way equal to those produced to-day, while his camera has never been excelled. Curiously enough, although this movement has been superseded, there is a tendency among expert workers to revive it, and many cameras specially built have been fitted with it.

The movement more commonly used is that known as the "claw." It is simple, and has the advantage of bringing the film into place for an exposure with a sharp, quick jerk. But it is a movement which requires to be designed very finely in order to perform its work smoothly and evenly, and without inflicting any injury upon the film.

The claw consists of a small lever in duplicate, which is so mounted as to have an eccentric movement and is driven direct by the main gear wheel rotated by the handle. The free upper end of each arm of the lever has a projecting pointed tooth of sufficient size to engage with the perforations on either side of the film. With the revolution of the wheel upon which it is mounted eccentrically the claw engages with the perforations, and, thus gripping the film after the manner of a ratchet and pawl, jerks it downwards a definite distance. When this downward movement is completed the claw disengages from the perforations and falls back clear of the film. Then the wheel, continuing its rotary movement, proceeds to lift the claw. When it has raised it to its highest point it brings it forward smartly to re-engage with the perforations, and causes a fresh downward movement of the film. The action is intermittent and occurs at regular intervals, while the movement of the film is always the same. Quick engagement and disengagement of the perforations is imperative for preventing the vibration and tearing of the film.

Fig. 1.—Mechanism of camera showing threading of film.

The mechanism of the camera may be understood from the diagram (Fig. 1), which refers to the Williamson instrument. The sprocket A is driven directly by the operating handle, which engages with the sprocket spindle. This sprocket A is fitted with two rows of teeth, mounted upon its periphery, and so spaced apart, both circumferentially and transversely, as to coincide with the distances between the perforations of the film. A pair of twin rollers, D and E, bear against this sprocket under the tension of a spring, their object being to keep the film pressed firmly against the sprocket. The teeth engage with the film perforations, so that by the rotation of the handle and sprocket the film is fed forwards regularly, smoothly and evenly, as it is drawn from the loaded spool box B.

The film is brought into position before the lens by passing through what is known as the "gate." This device H consists of two parts of which the first is fixed irremovably while the second is hinged to the first at one side and kept flat against it by means of a spring. Both of the parts are provided with an aperture or window, the exact size of a cinematograph picture—1 inch wide by ¾-inch deep—through which the light passes, after admission through the lens, to strike upon the sensitized surface of the film. There is just sufficient space between the two parts of the gate to permit the film to move easily, and its object is to hold the film perfectly flat and steady during the period of exposure. Each picture is thus kept in absolute focus.

The feed through the gate is accomplished by the claw N, which is mounted upon the eccentric O as already described. At the instant of exposure the claw is free of the film, or in the "out position," as it is termed, so that the sensitized ribbon is absolutely still. When an exposure has been made, the claw, having risen to the highest point of its travel, re-engages with the film and jerks it down ¾ inch, so as to bring a fresh unexposed surface before the lens. As the film emerges from the gate it is picked up once more by the sprocket A, the engagement of the perforations in the film with the sprocket teeth being assured by the two rollers J and K. The film then passes under the guide roller L, and is wound up on the bobbin M in the exposed film box C, the bobbin being worked through the handle that drives the mechanism.

The rotation of the handle also ensures, through gearing, the revolution of the shutter P, whereby the lens is eclipsed intermittently. The shutter is a ring fitted with an opaque sector which comes before the lens and shuts out the light during the movement of the film through the gate H by the claw N. In the Williamson camera this shutter is recessed into the case.

Although the lens may be of the fixed focus class—the focussing distance varying with the stop used—focussing can be carried out independently if very critical work is required. In the case of the Williamson camera and others of this type, focussing is accomplished by opening the shutter and the side of the camera and looking through the gate. In some cameras a focussing tube is provided. This passes from the gate to the rear of the instrument, through a space provided between the superimposed film dark-boxes. It is telescopic at the forward end. Thus, when focussing is being carried out, it can be extended so as to come flush with the gate, and pushed back out of the way when all is ready for working, so that the free movement of the film is not obstructed in any way. The rear end of the tube, which extends through the rear face of the camera box, is fitted with a cap to save the film from being fogged by light entering from behind.

One conspicuous advantage of the Williamson machine is that the whole of the mechanism is mounted upon a skeleton casting fixed to the interior of the mahogany case by means of four screws. By withdrawing these the whole of the internal mechanism may be removed intact, and much trouble is saved when inspection or repairs are necessary.

In some cameras the intermittent movement of the film is effected by a single claw which engages with the perforations upon one side of the film only. But this movement is not perfect. All the pulling strain is thrown upon one side of the film. This gives it a tendency to move unevenly into the gate and also increases the risk of tearing.

The driving gear of the camera is so adjusted that one complete revolution of the handle completes eight exposures. Consequently two revolutions have to be made per second to maintain the necessary speed of sixteen pictures per second. In the Williamson camera this is emphasised as a fixed speed in ordinary working, and any compensations demanded by the varying intensity of the light are made by altering the aperture of the lens. This is a logical method, for if the operator is required to make such compensations by varying the speed of his handle he is apt to obtain an indifferent result. It requires a very skilled operator indeed to vary the speed of the handle with judgment between the narrow limits possible. In some cameras this compensation for light is effected by varying the area of the opaque section of the shutter, but this is not so simple or effective a method as the variation of the stop. The latter can be accomplished while the camera is being driven, but in the former it is necessary that the work should be stopped while the front panel camera is opened and the shutter adjusted.

As for the tripod, one cannot be too careful in choosing it. This apparently insignificant detail has a far-reaching effect upon the picture results. Any ordinary tripod used in photographic work may suffice, but its absolute rigidity is essential. A tight head, too, is most necessary, without which the operator will get a side-to-side sway upon the picture. It must be borne in mind that in turning the handle there is a tendency, especially at first, to exert an unequal pressure upon the handle side of the camera, and, unless the support and its head are kept absolutely rigid, the pictures will betray evidences of the defect. The telescopic ladder tripod is very handy for topical work. This, when it is extended and when the camera is fixed, brings the lens some 7 feet above the ground. A cross-rail placed from 12 to 25 inches above the ground, and attached to the rear legs, offers a platform upon which the operator can stand to work his instrument. In this way both camera and operator are brought above the heads of the crowd, and an uninterrupted view can be obtained.

For moving-picture work a special type of tripod head has been evolved, which allows the camera to be moved bodily through both the horizontal and the vertical planes while exposures are being made. Thus it can follow a subject travelling in either of these directions. The movements are upon the rack and pinion principle, a small handle being fitted to each motion so that either can be operated independently of the other. By means of this panoramic attachment the main object in the picture, such as a carriage or an aeroplane, may be followed in either direction. But if both movements are to be completed simultaneously, the operator will require help. One person must sight the object and keep it in the picture by the manipulation of the two handles governing the respective movements of the tripod head, while the other confines his energies to turning the camera handle.

Although the moving-picture camera is built substantially and strongly, its mechanism is comparatively delicate. While it will withstand the hardest descriptions of legitimate work, it succumbs readily to brutal treatment. Although operated by means of a handle, it is neither a coffee mill nor a barrel organ, but a sensitive scientific instrument, and it must be treated as such if the finest results are to be obtained. Rough usage will throw out the registration and alignment. If handled carefully a camera should perform its task for years without needing repair. The effects of wear and tear can be mitigated very appreciably by keeping the moving parts well lubricated with good oil, such as is used for clocks, which neither gums nor clogs the bearings, nor injures the mechanism in any way.

Contents

Index

CHAPTER IV
THE CAMERA AND HOW TO USE IT

Having examined the mechanism of the moving-picture camera, and the broad principles upon which it works, we must now study the way to use it.

The first step is to load the film box, an operation which must be carried out in the dark room. The film is sold as a rule in standardised lengths, such as 100, 200, 350 feet, etc. With the ordinary type of camera the 100 or 200 feet lengths are used. For topical work either are quite adequate as a rule.

As has been said, the film is supplied perforated and ready for use. Many firms that sell the "stock," as the unexposed film is called, attach a blank or unsensitized "lead" to one end of the roll, for the purpose of "threading-up" the camera. If this is not supplied, and if the operator wishes to avoid the waste of 2 or 3 feet of sensitized ribbon, the deficiency can easily be remedied. For the blank "lead" all that is required is about 3 feet of useless or spoiled film which, however, should not be torn or cracked. The emulsion at one end of this should be scraped off for a distance of about ¼ inch. A pocket knife will do this very efficiently. The blank should then be laid flat upon the table, emulsion side uppermost, preferably upon a sheet of glass which secures a smooth, clean, level surface, and a little film cement applied to the scraped end of the blank. Film cement can be obtained readily and cheaply in small bottles complete with cap and brush. A bottle should always be kept to hand as it is often required, especially in joining up successive lengths of film; but if it should so happen that none is available at the moment, glacial acetic acid may be used with equal success, although it demands more careful handling. In an emergency alcohol constitutes a first-class cement, but it requires extreme care and skill because it is a solvent of the celluloid base.

After the cement has been applied to the cleaned end of the blank lead, the end of the unexposed coil of film is laid upon it, emulsion side uppermost, the overlap being about ¾ inch. Care must be exercised to see that the joint is made perfectly square and that the perforation holes of each piece of film come dead true, otherwise there will be trouble in passing the joint through the camera mechanism. When it has been superimposed satisfactorily, pressure must be applied to secure perfect adhesion. In order to ensure perfect jointing a film jointer should be used: in fact it is an indispensable and inexpensive tool.

When attaching the blank lead every precaution must be taken to protect the spool of unexposed film from light; only a very faint ruby glow should be used, for the cinematograph film is extremely sensitive. The cement dries rapidly, and the joint being found to be perfect the dark box should then be loaded. The coil of ribbon is slipped over the central bobbin. A hole large enough for this purpose is always left in the coil. The end of the lead is then passed through the velvet-faced slot near the bottom of the box. In order to prevent the loose end slipping back into the box, in which event there must be another journey to the dark room, it should be bent back and re-entered into the slot so as to form an external loop. The dark box is then closed, and securely locked, and is ready for insertion in the camera. It is advisable to carry at least two loaded boxes, especially if each is only of 100 or 200 feet capacity. The camera is provided with two dark boxes, one placed above the other. The upper box carries the unexposed film, while the lower receives the ribbon after exposure.

The camera may then be "threaded-up," or, if focussing is desired, this can be completed first. With the Williamson camera focussing is unnecessary within certain distances owing to the fixed foci of the stops. These will be explained later. Many other manufacturers of cameras follow the same principle, and it is most convenient for every-day work. Yet it may happen that the operator desires to focus critically. In this event he opens the side of the camera, lifts the pressure plate of the gate, and inserts into the gate window a small length, about 2 inches, of matt film, with the matt side towards the lens. The matt film serves exactly the same purpose as the ground-glass in the ordinary plate camera. The handle is revolved until the lens is opened, and the image thrown upon the matt film becomes apparent. This can then be focussed by moving the milled focussing screw on the lens until the picture stands out as sharply as is desired. At first the operation may appear to be somewhat awkward, because the operator has to look upon the matt film at an angle. It is easier in the case of a camera fitted with a focussing tube, for the operator has then merely to open the side of the machine to insert the matt film and push the telescopic tube out to its fullest extent to bear against the gate. By removing the cap from the tube upon the rear face of the camera, and looking through it as if through a telescope, he is able to look squarely upon his screen.

When focussing is complete the matt film is withdrawn and placed in a safe position. It is a good plan to clinch it to the bottom inner surface of the camera with drawing pins, for it can then be found when it is wanted. Should the piece be lost the defect can be repaired as follows. Take a small bit of waste film; scrape off the gelatine emulsion; and rough the celluloid surface with a piece of sandpaper; or even with a rough stone surface. It is well to carry a few inches of spoiled film in the pocket for such an emergency.

The film may now be threaded up. The loop of blank projecting from the dark box is picked up and the coil within is steadily unwound as the threading proceeds. The blank is first passed under the pressure roller (marked D in Fig. 1), and then under the spring roller E, which can be lifted for this purpose. It must be seen that the teeth of the sprocket engage with the perforations in the film. A loop G is then made and the film is threaded through the gate H. Before this can be done the claw N must be thrown in the "out" position to obtain access to the gate, which is done by turning round the eccentric. The spring part of the gate is then opened on its hinge, and the film is slipped in from the side. Care must be observed that an ample loop is left above the gate. When the gate is closed once more another loop I similar to that above the gate, is formed. The film now is passed round the under side of the sprocket A, the spring roller J being pressed back to admit of easy entrance, and the end of the blank is passed under the second or pressure roller K. Here again one must be careful to see that the insertion is square and that the sprocket teeth mesh with the film perforations. The film is then carried under guide roller L and through the velvet-faced slit into the empty film box C. This must be opened to permit the free end of the lead to be secured to the centre bobbin M, on which the film is wound in after exposure. The handle should be given a few turns to see that threading has been carried out properly, and also that it is properly attached to the bobbin M. If a sufficient length of blank is attached to the end of the unexposed film, and a piece of gummed paper is fixed on the lead about 6 inches in advance of the joint, it is possible to continue winding in on the lower bobbin until this mark appears at the mouth of the loaded dark box.

If the threading has been accomplished properly the interior of the camera should be as shown in the illustration facing p. 42. Here both film boxes are shown open, though of course the upper one is kept closed during the threading process. The most important part of this operation is the formation of ample loops both above and below the gate. Once formed they remain constant, because of the action of the teeth on the sprocket; for the movement of the ribbon over the sprocket is equal to that produced by the claws through the gate. At first sight the necessity of these loops may not be apparent, but when it is remembered that the film is moved through the gate intermittently, sixteen times per second, with a vicious jerk, it will be seen that if there were no loop, and the film were drawn directly from the dark box, a great strain would be imposed upon it, and probably it would break. But by providing the loop an elastic feed is secured, and the film is jerked into position before the lens with the minimum of vibration and without any risk of tearing or displacement.

Threading completed the lower dark box is closed and secured, together with the side of the camera, so that the whole of the interior is light-proof. The camera should not be re-opened after photographing has commenced until the whole of the film in the loaded box is exhausted, or, if the supply is not used, until the dark-room is regained, unless the waste of a foot or two of film is a secondary consideration. Should it become necessary to open the camera in the field, the handle should be given two or three turns to make sure that the last picture taken is wound into the exposed film box and is thus secure from the light. Opening the side of the camera obviously ruins the whole of the unexposed film threaded through the mechanism, so that when picture taking is resumed the handle must be given a few more turns to make sure that the whole of the light-ruined film has passed through the gate. Seeing that one turn of the handle represents eight exposures, equivalent to 6 inches of film, it is a simple matter to estimate how many turns of the handle are necessary to clear the gate of spoiled film.

Most cameras are provided with a film indicator enabling the operator to tell at a glance how many feet of film have been exposed. In this case, care must be taken to see that the indicator is returned to zero when the mechanism is threaded-up.

Another convenience is the "punch" whereby it is possible to mark the film after an incident has been photographed, so that the worker can afterwards tell in the dark room by a mere touch where the exposure ended in each case. The film should be marked after every episode is finished because it is then possible, if desired, to develop the film in lengths. Indeed it is advisable to follow this practice, and especially when the exposures have been made under varying conditions of light. By developing in sections one gets lengths of uniform density—a great assistance in printing.

The Williamson Camera threaded ready for Use.

The film is taken from the upper unexposed film-box, passed over the sprocket, through the gate, under the sprocket and wound into the lower exposed film-box.

The Lens of the Williamson Camera.

(For explanation see p. 43.)

The Adjustable Shutter of the Jury Camera.

In cinematography, as in ordinary photography, the judgment of the brilliance of the light and of the right stop to use on each occasion, is the one important factor for which mechanical provision is impossible. This is because of the extreme variation of the light conditions. But, while no hard and fast rules concerning exposure can be laid down, it is possible to give the beginner a little guidance to keep him on the safe side. Practice alone can make perfect, and experience is the more necessary because the cinematograph is an all-the-year-round machine. In topical work the operator is compelled to make the most of the existing weather conditions, no matter how deplorable they may be.

Under these circumstances it is well to have what might be termed a very flexible lens. The lens, that is to say, should be fitted with the means of varying the size of the aperture, and varying it within wide limits, according to the light conditions. The simplest way of achieving this is by means of what is called an iris diaphragm.

To illustrate the functions of the iris diaphragm we will take the Williamson instrument. This is fitted with a Zeiss-Tessar lens of 2-inch focus. By the aid of the iris diaphragm the diameter of the aperture may be varied from approximately ⅗ to ⅛ of an inch. Now it is obvious that more light can be passed through the lens with the larger, than with the smaller, aperture. While the larger aperture would do excellently for filming a football match on a dull day in mid-winter, it would be useless for a seascape on a cloudless day in July. For the latter the smallest aperture would suffice. But the requirements between these two extremes must be met: in other words the aperture must be adapted to intermediate demands. By turning the milled ring in which the iris diaphragm is mounted the size of the aperture can be varied even to a minute degree and thus adjusted to any sort of light conditions. For the guidance of the operator the total rotary travel of the ring is graduated to six different definite points or as many different sized apertures. These are as follows:—

f

/

3·5

gives

an

aperture

⅗-inch

in diameter

(nearly)

 

4

"

 

"

½-inch

"

   

5·6

"

 

"

⅓-inch

"

"

 

8

"

 

"

¼-inch

"

   

11

"

 

"

⅕-inch

"

"

 

16

"

 

"

⅛-inch

"

 

Although the differences between these successive apertures are very slight, they exercise a very appreciable effect upon the volume of light passing through the lens, and accordingly the period of the exposure. Thus although stop f/5·6 only decreases the size of the aperture by ⅙ of an inch over f/4, yet the effect of this reduction is to necessitate twice as long an exposure as is suited for the latter stop. Similarly f/8 demands twice the exposure of that required for f/5·6, and so on, the exposure being doubled with every diminution of the stop up to the limits of the diaphragm. Yet in practice this increase of exposure between two stops is impossible, because the handle must be turned at a definite speed. It is obvious, therefore, that compensation must come from another quarter. Instead of increasing the duration of the exposure we must have a greater intensity of light for f/5·6 than for f/4.

At first sight the beginner might be disposed to think that the selection of the most favourable aperture is a matter demanding extremely fine judgment and skill, especially when there are other factors which may upset calculations. Many other advantages arise from using as small an aperture as possible, such as increased sharpness of the picture, especially at the edges. Mr. Williamson the designer of the camera has realised this, and as a result of his unique experience, he has set down some very useful rules to guide the beginner, as to which stop should be used for varying conditions of light and subject. In elaborating this advice Mr. Williamson rightly commences from the zero point as it were, taking moving-pictures of a football match on a dull winter afternoon, when, owing to the feeble light, the capacity of the lens and the sensitiveness of the film are strained to the utmost. From this point he has graduated the diaphragm and its use as follows:—

Stop.

Subject and Conditions.

F/3·5

On a dull winter's day; well-lighted interior: or on a subject at any time of the year where there are heavy shadows such as under trees.

F/4

On a bright day in winter: on dull days in spring and autumn.

F/5·6

Outdoor exposures during September, October, March, and April. Dull summer weather.

F/8

Street scenes in bright summer weather.

F/11

Open fields in bright sunshine.

F/16

Bright sea and sky subjects.

It must be understood that the foregoing are not set down as hard and fast guiding rules, but they may be safely taken as some indication of what should be done under such varying conditions. They may be said to apply generally to the temperate zones where the conditions are almost identical, irrespective of geographical situation. If the beginner follows them at first he will not make very serious mistakes. But, as has been said, experience alone can finally determine the factor of lens aperture.

The size of the aperture has another far-reaching effect. This is in regard to focussing. With the 2-inch Zeiss-Tessar lens of the Williamson camera when the largest aperture is used, nothing important in the picture should be within a distance of 20 feet. If it is, it will not be in focus. As the diaphragm is closed this distance decreases proportionately until the infinity, INF, mark is reached. At this point practically everything is in focus. The distance when other objects are in focus at the respective stops is as follows.

f

/3·5

focus

distance

20

feet

f

/4

"

"

20

"

f

/5·6

"

"

15

"

f

/8

"

"

12

"

f

/11

"

"

10

"

f

/16

"

"

5

"

INF

"

"

everything.

At first sight the fact that the camera is operated by the turning of a handle makes it seem to be absurdly simple. One or two experiments however, will prove that it is far from being as easy as it looks. The salient point is to turn the handle steadily and evenly so as to complete two revolutions per second. The first pictures will be found to be very unsatisfactory, having an eccentric jerky effect instead of a smooth easy animation. An even pressure must be maintained throughout the complete rotation, and, before the beginner attempts to take any pictures and thereby waste expensive film, he would do well to practise handle-turning until he has become proficient. If the turning movement is timed with a watch, and "one" corresponding to a second is counted for each double turn, a perfectly steady turning movement will soon be attained. Some cameras are fitted with an indicator which records the number of feet of film consumed. But no anxiety need be felt if this convenience is absent. The operator need only count one, two, three, and so on, while turning the handle, each number representing a double turn. In this way, as 16 pictures, equivalent to one foot of film, are made with every double turn and every one count, the number reached at the end of the task will show how many feet of ribbon have been used, and if this is deducted from the amount originally held by the loaded box it is easy to tell the length of film unused. When the upper box has been exhausted and the lower box filled, the latter is withdrawn and packed away to be opened in the dark room only. The empty upper box is taken out and slipped into the lower position to act as a receiver from the next loaded film-box.

In photographing, the operator must keep his eyes riveted upon the view finder, to make sure that the subject he desires is in the field of the lens. The movements can be followed easily, and there should be no difficulty in keeping the most important part of the subject in the centre of the picture.

To follow the subject either in a horizontal or vertical plane it is necessary to turn the handle controlling the panoramic movements of the tripod head. This mechanism should be turned slowly and steadily with one hand, while the other is turning the camera handle. It is by no means an easy, simple matter to follow a subject in this way without any disconcerting jerky movement, since it involves doing two things at once. For a beginner it is particularly exacting, as an eye must be kept fixed upon the view finder to follow the moving object. But after a little experience the whole of these movements are carried out in a semi-mechanical manner. In cinematography, it is the diligent, careful, and persevering worker who scores successes. In the beginning failures may be galling and frequent, but practice and experience are the best teachers. One can soon become adept in a fascinating art.

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Index

CHAPTER V
HAND CAMERA CINEMATOGRAPHY

During the past few years competition among professional moving-picture photographers has become exceedingly keen, especially in connection with the filming of topical events. The operator often is faced with prodigious obstacles, the subjugation of which is not always easy, or even possible. For instance, in a dense crowd the conventional apparatus, from its bulkiness, weight, and proportions, cannot be handled, and, even if set upon its tripod with the lens elevated above the heads of the people, there is the serious danger of the whole being upset by the swaying motion of the mass of spectators. Yet at the same time a place in the crowd constitutes an ideal point of view.

Again, there are many situations where the use of a tripod is impracticable, if not dangerous. Take the aeroplane. An operator seated in a flying machine and desirous of recording the moving scenes beneath, cannot support his machine upon the conventional device for this purpose. He has to hold it as best he can, and so secure his pictures under extremely trying conditions. Although films innumerable are taken by persons seated in aeroplanes, only a very small proportion ever come before the public eye, for the majority are failures. Nowadays, also, the filming of aeroplane flights from a fixed point on the ground is by no means easy. In order to follow the evolutions of flying machines, more particularly at comparatively close ranges and when travelling at high speeds, two operators are required, one to turn the camera handle, and the other to sight and follow the object both through its horizontal and vertical planes in such a way as to keep it in the centre of the picture. To do this he has simultaneously to turn the two handles operating the panoramic and elevating gear of the tripod head, and often in opposite directions. The task must be done without the slightest jerk, or the success of the film is marred. One of the most disconcerting effects upon the screen is a jumpy panoramic movement either horizontally or up and down. It worries the eye, and more often than not reduces the picture to an almost unintelligible blur.

The "Aeroscope" Moving-picture Hand Camera.

A. Air valve. B. Button for varying photographing speed during exposure. C. Exposure button.

The Compressed Air Reservoirs of the "Aeroscope" Camera.

One charge is sufficient to expose 600 feet of film.

But perhaps the most unnerving and difficult conditions under which moving-pictures can be taken are those pertaining to the filming of wild animal life at close range under natural conditions. In this case a good nerve, a steady hand, and acute presence of mind, are indispensable. A wild elephant trumpeting madly and dashing towards the camera at full speed, or a lion springing towards the operator may form the subject for a thrilling incident in a film, but does not inspire confidence in the cinematographer. Under such conditions a tripod outfit is worse than useless. It not only endangers the operator's life, but the pictures taken under such conditions are invariably of poor quality, even if they survive the results of the animal's mad frenzy. To stand one's ground and to keep turning the camera handle steadily at two revolutions per second up to the last moment with the sang-froid of someone filming a street procession would put too great a strain on human nature. Even the coolest man would not obtain first-class results at uncomfortably close quarters. Instead of turning the handle in a steady rhythmic manner the motion would be in a series of erratic jerks, some fast and some slow, producing a result which the public would ridicule. Mr. Cherry Kearton, whose pictures of jungle life constitute some of the marvels of the cinematographic art, considers that this branch of cinematography cannot be excelled for thrilling excitement. The operator must stand his ground undismayed, because the close-quarter pictures are always the most fascinating. Yet at the same time he must keep a corner of one eye fixed upon an avenue of retreat, so that he can get clear in the nick of time when the crisis arises. The attention given to the photographic work must be reduced to the absolute minimum, so as to be practically automatic; the camera must be as small and as compact as possible, for the only way of escape lies often up a tree.

Several inventors have devoted their energies to the evolution of a reliable hand-camera, capable of fulfilling the same duty in cinematography as the snap-shot instrument in still-life work. The tripod was sacrificed, but then there arose another difficulty. This was in the necessity of moving the film mechanism by means of the handle. In fact, under many conditions of working, such as in the jungle, it would be quite impracticable. What was required was an efficient moving-picture machine, small, light, and compact, working upon the principle of "you-press-the-button-and-I'll-do-the-rest."

It is a perplexing problem to solve, and the first commercially practicable idea in this direction was conceived by the Polish scientist Kasimir de Proszynski. He has produced a camera completely self-contained and wholly automatic in its operation. Dimensions and weight have been kept down. In loaded condition, with 300 feet of film, it is 12 inches long, 8½ inches wide, 6½ inches deep, and weighs only 14 pounds. It works upon the "press-the-button" system, the film-moving mechanism and shutter running the whole time the button is depressed. The power comes from cylinders of compressed air by which a tiny engine is driven. All that the operator has to do is to sight his subject and to keep his finger on the button, while he follows the object on the view finder.

When this camera, known as the "aeroscope," appeared upon the market, it aroused considerable interest, but its reliability was doubted. It was not until Mr. Cherry Kearton decided to give it a trial that it came to be regarded more seriously as a feasible moving-picture machine. This naturalist-cinematographer took it with him on one of his expeditions, and was able to record some startling incidents which would not have been possible otherwise. Familiarity with the camera and experience in the field convinced him of its serviceability, provided that certain modifications were effected. These were carried out, and the camera is now regarded as an excellent instrument for work that could not be achieved by any other machine.

It is fitted, as has been said, with a small engine driven by compressed air. The air is stored in six small cylinders of an aggregate capacity of 600 feet. This is sufficient to expose 600 feet of film. The cylinders are charged with air in the manner of a motor tyre and with a similar kind of pump. An indicator on the side shows constantly the air pressure remaining in the reservoirs, while a regulator enables the speed to be varied. The driving mechanism is very light, small, and compact, and contains but a small number of parts, so that the risk of failure is not great. Though it constitutes the most delicate part of the whole mechanism, and requires careful handling, it works remarkably well so long as it is kept clean and well lubricated.

Another prominent feature of the mechanism is what is termed an equilibrator. Practically speaking this is a small gyroscope, and is introduced to subdue any small vibrations or tremblings which arise while the instrument is working. This part of the mechanism has been criticized on the ground that a gyroscope, to be effective, must be of appreciable weight. Many operators dispute the necessity for its introduction. They point out that the beneficial effects are not proportionate to the extra weight involved. Furthermore, being an additional piece of mechanism, it enhances the risk of derangement. Against these contentions, however, the operators who have worked the instrument maintain that it nullifies all the vibrations set up by the driving mechanism, which, though apparently slight, would otherwise suffice to spoil the pictures. Seeing that the sole object of employing this camera is the elimination of a rigid support such as a tripod, it certainly seems worth while, even at the cost of added weight, to gain some compensating steadiness. And the vibration of the air engine increases the need.

The Lens, Shutter, Compressed Air-driven Mechanism, and Gyroscope, which counteracts slight Vibrations, of the "Aeroscope."

Loading the "Aeroscope" Camera.

The unexposed and exposed film-boxes are mounted upon one spindle.

In operating this instrument the usual method is to hold the camera against the chest and one cheek, thereby bringing the eye on a level with the sighting piece. By letting the elbows rest against the body the weight is easily and steadily supported. Held in this position the minimum of fatigue is felt by the cinematographer, while he is given complete control over the mechanism. It can also be used when the operator is on horseback, the method of support being virtually the same. But in this case only one hand is used; the other is left free to control the horse. Another advantage of the system is the ease with which the camera can be swung round in order to follow a moving object steadily.

Photographers who use a hand-camera are familiar with the disturbances set up by the motion of the body in breathing. This is often sufficient to spoil a picture if care is not displayed at the instant of exposure. With the aeroscope—owing to the exposure being from 1/32 to 1/50 of a second, relatively long in comparison with snap-shotting where the exposure is often only the 1/200, or even less, of a second—these disturbances are somewhat more acute. Considerable practice is required before this difficulty can be overcome. Some operators who have used the aeroscope prefer to utilise a convenient support, if available, such as a wall, or the stump of a tree, thereby making sure of a solid rigid foundation. But in cinematography the ill-effects arising from respiration are not so serious as in still-life work. A picture here and there may show its effects, but they pass unnoticed. They are subdued, as it were, by the unblemished pictures which precede and follow.

Another camera of this type is the "Jury Autocam" which, as its name implies, works upon the automatic "press-the-button" system. This camera is fitted with a small electric motor, driven by a small dry battery, and brought into action by the pressure of a button. A small side-lever controls the picture-taking speed, which can be varied while the mechanism is running. The camera itself is exactly similar to the "Jury Duplex" model, the only addition being a small separate case, about 2 inches in depth, fitted to the base of the instrument, and a covered chain gearing on one side for transmitting the power from the motor to the camera mechanism. This camera likewise is fitted with a small balancing apparatus to counteract slight vibrations.

Mr. Cherry Kearton steadying himself upon a precipice to take pictures of bird life.

Mr. Cherry Kearton slung over a cliff, showing the operation of the hand camera.

The "Aeroscope" Camera in the Field.

From the "Cinema College," by permission of the Motograph Co.

Vulture preparing to Fly.

In such instruments as these the even running of the motor is a vital factor. It must not run any faster when the reservoir or battery is fully charged than when it is nearly exhausted, nor must there be any variations of speed, for eccentricities of this sort are apt to spoil the film. The governing therefore requires to be most delicate and thorough. Another difficulty is the incorporation of a reservoir capable of carrying a sufficient quantity of air at the necessary pressure to drive the length of film for which it is rated. In the "Jury Autocam" a length of 100 feet can be driven on a single battery charge. This is adequate for many purposes, but a length of at least 200 feet is generally to be preferred. The camera is being adapted to meet these conditions, and it is anticipated that no more difficulty will be met in consummating this end, than was involved in making the camera drive a 100 feet length.

While it is a moot point whether the automatic cinematograph camera will ever displace the orthodox machine entirely, it is a useful and even indispensable machine for working under difficulties. It has been used in the aeroplane and has been found successful. It is also of the utmost use in close-range dangerous work, or in situations where the turning of the handle by hand is liable to be carried out imperfectly and unsteadily. The aeroscope camera has been used on many notable expeditions such as those of Paul Rainey, and others in Africa, and is used exclusively by Mr. Cherry Kearton in his daring work in tight corners. Many of the thrilling and exciting pictures taken in the haunts of wild animals have been secured therewith, and these films show convincingly what can be done with the instrument when it is handled by an expert.

But the true province of the hand cinematograph camera undoubtedly is in connection with rush work. For the filming of topical incidents it is invaluable. The operator is not trammelled with a bulky outfit. He carries his camera in his hand or slings it across his back in the manner of a knapsack. When he wishes to film an incident he is not harassed even by the crowd. He is not compelled to set up a tripod or to climb to an elevated point to get clear of the sea of heads. He can hold the camera above his head, and by means of a second and special view finder placed on the under side of the instrument he can sight and follow the subject while pressing the button. Thus he records the episode as easily as if he were placed in the most advantageous raised position, and could manipulate the machine in the orthodox manner. When his work is completed he can get away without any delay, because the small box contains everything.

On the whole, however, the hand moving-picture camera is scarcely yet a suitable instrument for beginners. The invention is in its infancy, and although clever men are striving to make it more simple and reliable, many peculiar problems still remain to be solved. But in the hands of an expert operator it is capable of doing first-class work.

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