Part 5

Our illustrations are from "Photographic Pastimes" by Herman Schauss.

With a very wide-angle lens it is also possible to make a photograph of a little suburban garden, and it will appear to resemble a park or palace grounds. This is a trick often adopted by auctioneers and estate agents, so that in viewing photographs of property, it is really impossible to form any safe idea regarding the place itself.

CONICAL PORTRAITS.

Amusing caricatures may be obtained by deforming the sensitive surface of the negative. The accompanying conical portrait is one.[6]

[6] From "Les Recreations Photographiques."

To depict the features of a person on a paper cone is not an easy matter; whilst to obtain them by photography is a tolerably simple operation.

Having glued on the interior face of a plate-holder (the slide being drawn), in the place of a sensitive plate, a cone made of strong cardboard, superpose on it an unexposed film which has been cut to the form of the development of the cone (as shown in Fig. 77). The film is secured by means of two or three pins. Having focused on a point of the subject in a middle plane, the ground glass is afterwards drawn back a distance equal to half the height of the cone, taking care not to derange either the subject or the objective. To obtain a sharp image a very small diaphragm must necessarily be used, but with a rapid plate and good light that is of little moment. The camera should be placed in the dark room, the lens being inserted in a hole in the partition just its size, and the subject in the adjoining apartment opposite the lens--this because the cone will not allow the plate-holder to be closed by the slide.

Fig. 76 shows the arrangement of the camera and holder. The exposure made, the film is developed, as usual. The negative gives a print deformed as shown in Fig. 76. The original, if not grotesque appearance of the head disappears when the print is rolled into a conical form and the observer places his eye in the prolongation of the axis of the cone. Fig. 78 shows the head as seen under these conditions.

MAKING DIRECT POSITIVES IN THE CAMERA.

Prepare a saturated solution in water of the crystals of thiosinamine, and add from two to eight minims of it to an ordinary pyro or eikonogen developer. Expose rather less than usual. The effect of this addition to the developing agent is an entire reversal of the image, a positive instead of a negative being obtained. Ammonia will assist the reversal. Colonel Waterhouse, the discoverer of this process, recommends in some cases the plates being subjected to a bath of 5 per cent nitric acid and 3 per cent potassium bichromate before exposure, followed by a thorough washing.

INSTANTANEOUS PHOTOGRAPHY.

In the very earliest days of photography this term was applied to what would now be considered very slow work indeed. We now usually apply this term when the exposure does not exceed one second. In some cases this only amounts to the one-thousandth part of a second. This exceedingly brief exposure is usually given to the plate by means of a suitably constructed shutter.

The immense strides that have recently been made in instantaneous photography, owing chiefly to the advent of the dry-plate process, have caused photography to become useful to almost every branch of science.

To Muybridge and Anschutz we are greatly indebted for the strides made in instantaneous photography. These gentlemen have succeeded in photographing moving objects hitherto considered impossible to be photographed. Galloping horses, swift-flying birds, and even bullets and cannon balls projected from guns have been successfully photographed, showing even the little head of air driven along in front of the bullet.

Both Muybridge and Anschutz also succeeded in making series of twenty-four or more photographs of a horse during the time it makes a single leap, and thus illustrated its every movement. The value of these and other possibilities with the camera for artists cannot be overestimated. Its aid to meteorologists in photographing the lightning, to astronomers in stellar, lunar and solar photography, and to all other sciences would require a work as large as this to describe.

For the making of instantaneous pictures a large number of suitable cameras have been devised. In most of these the lens is a very rapid one, and in some cases so arranged that all objects beyond a certain distance are in focus. With an instantaneous camera a secondary image is necessary, so that the right second can be judged for making the exposure. This is usually produced by a finder. In making instantaneous exposures the following tables may be useful:

Approximate distance feet per second A man walking 3 miles per hour moves 4-1/2 A man walking 4 miles per hour moves 6 A vessel traveling at 9 knots per hour moves 15 A vessel traveling at 12 knots per hour moves 19 A vessel traveling at 17 knots per hour moves 28 A torpedo boat traveling at 20 knots per hour moves 35 A trotting horse 36 A galloping horse (1,000 yards per minute) 50 An express train traveling at 38 miles an hour 59 Flight of a pigeon or falcon 61 Waves during a storm 65 Express train (60 miles an hour) 88 Flight of the swiftest birds 294 A cannon ball 1,625

An object moving--

1 mile per hour moves 1-1/2 feet per second. 2 " " 3 " " 5 " " 7-1/2 " " 6 " " 9 " " 7 " " 10-1/2 " " 8 " " 12 " " 9 " " 13 " " 10 " " 14-1/2 " " 11 " " 15 " " 12 " " 17-1/2 " " 15 " " 22 " " 20 " " 29 " " 25 " " 37 " " 30 " " 44 " " 35 " " 51 " " 40 " " 59 " " 45 " " 66 " " 50 " " 73 " " 55 " " 80 " " 60 " " 88 " " 75 " " 110 " " 100 " " 147 " " 125 " " 183 " " 150 " " 220 " " 200 " " 257 " "

With these tables it will be very easy to find the distance that the image of the object will move on the ground-glass screen of the camera. To do this, multiply the focus of the lens in inches by the distance moved by the object in the second, and divide the result by the distance of the object in inches.

Example, find the movement of the image of an object moving 50 miles per hour at a distance of 100 yards with a lens of 9-inch focus.

9 × 876 = 7,884 ÷ 3,600 = 2-1/5 inches per second.

We must also find out the speed of the shutter required to take the object in motion, so that it will appear as sharply defined as possible under the circumstances. To do this the circle of confusion must not exceed 1/100th of an inch in diameter. We therefore divide the distance of the object by the focus of the lens multiplied by 100, and then divide the rapidity of the object in inches per second by the result obtained. This will give the longest exposure permissible in the fraction of a second. For example, we require to know the speed of a shutter required to photograph an express train travelling at the rate of 50 miles per hour at a distance of 50 yards with an 8-1/2-inch focus lens.

The train moves 876 inches per second.

1,800 distance in inches ÷ (8-1/2 × 100) = 1,800 ÷ 850 = 36/17.

876 speed of object per second ÷ 36/17 = (876 × 17)/36 = 413 = 1/413 second.

Given the rapidity of the shutter, and the speed of the moving object, we require to find the distance from the object the camera should be placed to give a circle of confusion less than 1/100th of an inch. Multiply 100 times the focus of the lens by the space through which the object would pass during the exposure, and the result obtained will be the nearest possible distance between the object and the camera. For example, we have a shutter working at one-fiftieth of a second, and the object to be photographed moves at the rate of 50 miles per hour. How near can a camera fitted with a lens of 8-1/2-inch focus be placed to the moving object?

Object moving 50 miles per hour moves per second 876 inches, and in the one-fiftieth part of a second it moves 17.52 inches, so that--

8-1/2 × 17.52 = 8.5 × 100 × 17.52 = 14,892 inches = 413 yards.

Instantaneous photography can only be successfully performed in very bright and actinic light, and should never be attempted on dull days, as underexposure will be the inevitable result. In developing it is necessary to employ a strong developer to bring up the detail. Some operators make use of an accelerator for this purpose, but it is not to be recommended; the simplest is a few drops of hyposulphite solution added to about 10 ounces of water. In this the plate is bathed for a few seconds previous to development.

The following is a table by H. E. Tolman showing displacement on ground glass of objects in motion:

============================================================== | | Distance on | | | |Ground Glass | | | | in Inches | Same with | Same with Miles per |Feet per |with Object 30|Object 60 Feet| Object 120 Hour. | Second. | Feet Away. | Away. | Feet Away. ----------+---------+--------------+--------------+----------- 1 | 1-1/2 | .29 | .15 | .073 2 | 3 | .59 | .29 | .147 3 | 4-1/2 | .88 | .44 | .220 4 | 6 | 1.17 | .59 | .293 5 | 7-1/2 | 1.47 | .73 | .367 6 | 9 | 1.76 | .88 | .440 7 | 10-1/2 | 2.05 | 1.03 | .513 8 | 12 | 2.35 | 1.17 | .587 9 | 13 | 2.64 | 1.32 | .660 10 | 14-1/2 | 2.93 | 1.47 | .733 11 | 16 | 3.23 | 1.61 | .807 12 | 17-1/2 | 3.52 | 1.76 | .880 13 | 19 | 3.81 | 1.91 | .953 14 | 20-1/2 | 4.11 | 2.05 | 1.027 15 | 22 | 4.40 | 2.20 | 1.100 20 | 29 | 5.87 | 2.93 | 1.467 25 | 37 | 7.33 | 3.67 | 1.833 30 | 44 | 8.80 | 4.40 | 2.200 35 | 51 | 10.27 | 5.13 | 2.567 40 | 59 | 11.73 | 5.97 | 2.933 45 | 66 | 13.20 | 6.60 | 3.300 50 | 73 | 14.67 | 7.33 | 3.667 55 | 80 | 16.13 | 8.06 | 4.033 60 | 88 | 17.60 | 8.80 | 4.400 75 | 110 | 22.00 | 11.00 | 5.500 100 | 117 | 29.33 | 14.67 | 7.333 125 | 183 | 36.67 | 18.33 | 9.167 150 | 220 | 44.00 | 22.00 | 11.000 ----------+---------+--------------+--------------+-----------

ARTIFICIAL MIRAGES BY PHOTOGRAPHY.

Some time ago a photographer made quite a sensation by the publication of a fine photograph of a mirage, a phenomenon frequently observed on the plains of Egypt. The wily photographer had, however, never traveled away from this country. He had simply produced the effect by artificial means. A method of making these pictures was given some time ago in the _Scientific American_. A very even plate of sheet iron is taken and placed horizontally on two supports. The plate is heated uniformly and sprinkled with sand. Then a small Egyptian landscape is arranged at one end of the plate, and the photographic instrument is so placed that the visual ray shall properly graze the plate. A sketch of the arrangement is shown in Fig. 82.

THE PHOTO-CHROMOSCOPE.

This instrument was devised by M. Paul Nadar, the celebrated French photographer, but anyone can construct a similar apparatus. The arrangement is shown in Fig. 83.

The slides A and B B are adjustable so that any sized picture can be inserted and the sides closed round it to shut out the light from behind. A silver print unmounted is made transparent with vaseline and placed on the glass. Pieces of paper of various colors are placed in the reflector, C, and by this means all kinds of effects can be obtained. A landscape can be viewed as though under the pale reflected light of the rising sun behind the mountains, which may be changed gradually to the full light of day.

COMPOSITE PHOTOGRAPHY.

This is a process of combining a number of images in such a way that the result obtained is an aggregate of its components. Francis Galton was one of the first to employ this system. In the appendix to his "Inquiries into Human Faculty," Galton has described the very elaborate and perfect form of apparatus which he has used in his studies; but entirely satisfactory results may be obtained with much more simple contrivances. The instrument used by Prof. Bowditch[7] is merely an old-fashioned box camera, with a hole cut in the top for the reception of the ground-glass plate upon which the image is to be reflected for purposes of adjustment. The reflection is effected by a mirror set at an angle of 45 degrees in the axis of the camera, and pivoted on its upper border so that, after the adjustment of the image, the mirror can be turned against the upper side of the box, and the image allowed to fall on the sensitive plate at the back of the camera. The original negatives are used as components, and are placed in succession in a small wooden frame which is pressed by elliptical springs against a sheet of glass fastened vertically in front of the camera. By means of this arrangement it is possible to place each negative in succession in any desired position in a plane perpendicular to the axis of the camera, and thus to adjust it so that the eyes and the mouth of its optical image shall fall upon the fiducial lines drawn upon the ground-glass plate at the top of the camera. An Argand gas burner with a condensing lens furnishes the necessary illumination.

[7] From _McClure's Magazine_, September, 1894.

"For our amateur photographers," writes Prof. Bowditch, "who are constantly seeking new worlds to conquer, the opportunity of doing useful work in developing the possibilities of composite photography ought to be very welcome. Not only will the science of ethnology profit by their labors, but by making composites of persons nearly related to each other, a new and very interesting kind of family portrait may be produced. The effect of occupation on the physiognomy may also be studied in this way. By comparing, for instance, the composite of a group of doctors with that of a group of lawyers, we may hope to ascertain whether there is such a thing as a distinct legal or medical physiognomy."

TELEPHOTO PICTURES.

During the last few years many so-called telephotographic lenses have been placed upon the market. These instruments enable one to photograph objects in the distance and obtain images very much larger than those given by the ordinary photographic lens. These lenses are, however, very costly. In an article by Mr. O. G. Mason, published in _The Photographic Times_ for June, 1895, that gentleman described a simple method of obtaining telephoto pictures by replacing the ordinary lens with an opera glass. He says: "Several devices have been brought forward with a view of decreasing the expense of telephoto lenses, but I have seen no others so satisfactory, cheap and simple, as the utilization of the ordinary opera glass for the camera objective, which was described, figured and finally constructed for me about a year ago by Mr. Alvin Lawrence, the horologist of Lowell, Mass. An opera or field glass is a convenient and useful instrument in the kit of any touring photographer; and when he can easily and quickly attach it to his camera-box as an objective its great value is at once made apparent. Mr. Lawrence's method of doing this at little cost is a good illustration of Yankee ingenuity. It is not claimed that such a device will do all or as well as a telephotographic lens costing ten times as much; but it will do far more than most people could or would expect. Of course the field is quite limited, which, in fact, is the case with the most expensive telephotographic objective, and the sharpness of the image depends much upon the quality of the opera or field glass used. The accompanying views show the relative size and character of image by a forty-five dollar rapid rectilinear view lens and a four-dollar opera glass attached to the same camera and used at the same point. The other illustrations show the camera as used and the method of opera glass attachment to the lens-board. It will be seen that the eye end of the opera glass is placed against the lens-board, one eye-piece in a slight depression around the hole through the centre, and by a quarter turn the brace between the two barrels passes behind a projecting arm on the board, the focusing barrel resting in a slot in this arm, where it is firmly held in position by friction alone.

As opera glasses are usually constructed for vision only, no attempt is made by the optician to make correction for securing coincidence of foci of the visual and chemical rays of light as in the well-made photographic objective. Hence, it is often found that the actinic focus falls within, or is shorter than, the visual. When this is the case, the proper allowance is easily made after a few trials.

LIGHTNING PHOTOGRAPHS.

The method of making photographs of lightning flashes is very simple. The camera is focused for distant objects. During a thunderstorm the camera is pointed in the direction of the flashes, a plate is inserted, the cap is removed from the lens, and as soon as a flash takes place the lens is covered up and the plate is ready for development. To avoid halation a backed or non-halation plate should be used.

PHOTOGRAPHING FIREWORKS.

Photographs of pyrotechnical displays can also be made at night. The method of procedure is the same as described for photographs of lightning. The camera is focused for distant objects and the lens pointed towards the place where the discharge takes place. Fig. 90.

DOUBLES.

Some very amusing pictures can be made by double exposure. For instance, Fig. 91 represents a man playing cards with himself. A method of making these is thus described by W. J. Hickmott in "The American Annual of Photography for 1894":

Fit an open square box into the back of the camera, having it fully as large as, or a little larger than, the negatives you wish to make. My attachment is made for 8 × 10 plates and under, and fits into the back of a 10 × 12 camera. In shape it is like Fig. 91, and I will designate it as A. The box is about 3 inches deep. When put into the camera it appears as in Fig. 92. Now have a plain strip of wood just one-half the size of the opening in A like B, Fig. 93. Have B fit very nicely in A, at the opening toward the lens, and so that it can be moved freely from one side to the other. It is very convenient to have a rabbet on the top and bottom of A so that B can be moved from side to side and maintained in any position.

To make a "Double," attach A to the camera as shown, put B into its place in the opening in A, say on the right-hand side as you stand back of your camera, thus covering up the right-hand side of the plate when exposure is made. Pose your subject on the left hand side, which will give you an image on the right-hand side of your ground glass and plate, draw the slide and expose, immediately returning the slide. This finishes one half of the operation. Shift B over to the left-hand side of A, which will cover up that portion of the plate just exposed, pose your subject again, but on the left-hand side, which will give you the image on the right-hand side of the ground glass and plate, draw the slide and expose out for the exact length of time as at first. On development, if the exposure on both sides has been correct, and of equal length, a perfect negative will be the result.

The camera must on no account be moved between the exposures, nor the focus changed. After making the first exposure the correct focus for the second is obtained by moving the subject backward or forward until an exact focus is secured, and not by moving the camera or ground glass. The whole apparatus should be painted a dead black.

When the attachment is in place it will be noted on the ground glass that while the strip B is just one-half the size of the opening in A, it does not cut off just one-half of the ground glass, a line drawn through the center of which shows that a space in the center of the plate about one-half an inch in width receives a double exposure, but this is not apparent in the finished negative. The figure should be posed as near the center of the plate as possible in each instance. This apparatus, as described, is only available for making two figures. By making B narrower, or one-third of the width of the opening in A, three figures may be made, using each time a separate piece to cover up that portion of the plate exposed, and by changing the form of B to that shown in Fig. 95, four positions can be secured.