Photographic Amusements Part 9

----------+---------+--------------+--------------+----------- 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 ----------+---------+--------------+--------------+-----------

[Ill.u.s.tration: FIG. 82.--ARTIFICIAL REPRODUCTION AND PHOTOGRAPHING OF A MIRAGE]

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 gla.s.s. 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.

[Ill.u.s.tration: FIG. 83.--NADAR'S PHOTO-CHROMOSCOPE.]

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-gla.s.s 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 gla.s.s 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-gla.s.s 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."

[Ill.u.s.tration: By Prof. Bowditch. FIG. 84.--COMPOSITE PORTRAITS OF BOSTON PHYSICIANS AND SAXON SOLDIERS.]

TELEPHOTO PICTURES.

[Ill.u.s.tration: FIG. 85.--CAMERA WITH OPERA GLa.s.s ATTACHED.]

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 gla.s.s. 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 gla.s.s 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, Ma.s.s. An opera or field gla.s.s 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 ill.u.s.tration 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 gla.s.s 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 gla.s.s attached to the same camera and used at the same point. The other ill.u.s.trations show the camera as used and the method of opera gla.s.s attachment to the lens-board. It will be seen that the eye end of the opera gla.s.s 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 pa.s.ses 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.

[Ill.u.s.tration: FIG. 86.--CAMERA SHOWING ARRANGEMENT FOR OPERA GLa.s.s.]

[Ill.u.s.tration: FIG. 87.--VIEW TAKEN WITH OPERA GLa.s.s.]

[Ill.u.s.tration: FIG. 88.--VIEW TAKEN FROM SAME SPOT WITH AN ORDINARY VIEW LENS.]

As opera gla.s.ses 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.

[Ill.u.s.tration: FIG. 89.--PHOTOGRAPH OF LIGHTNING MADE AT BLUE HILL.]

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.

[Ill.u.s.tration: FIG. 91.--A DOUBLE. BY H. G. READING.]

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":

[Ill.u.s.tration: By Leonard M. Davis. FIG. 90.--FAREWELL RECEPTION TO THE PRINCE OF WALES.]

[Ill.u.s.tration: FIG. 91.]

[Ill.u.s.tration: FIG. 92.]

[Ill.u.s.tration: FIG. 93.]

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.

[Ill.u.s.tration: FIG. 94.]

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 gla.s.s 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 gla.s.s 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.