ON THE PHOTOGRAPHIC DELINEATION OF THE PICTURES
CREATED BY THE KALEIDOSCOPE.
In a preceding chapter we have referred to the delineation of the
pictures created by the Kaleidoscope, when they are received on the
ground glass of a camera obscura, or when a camera lucida is placed
at the eye-end of the instrument. Both of these methods are very
imperfect, and when the pictures have been copied for useful purposes,
we believe that they have generally been executed by a skilful
draughtsman, who delineated carefully one of the sectors of which the
figure is composed, and then repeated it so as to complete the picture.
[Illustration: FIG. 52.]
Since the invention of the Kaleidoscope, the discovery of the
photographic art—of the Daguerreotype and Talbotype processes, has
given a new value to the instrument. By means of a Kaleidoscope Camera,
the most complex figures can be almost instantaneously transferred to
paper, or to plated copper, and hundreds of designs offered to the
choice of the artist who is to employ them. The very same figure which
is obtained by one mode of illumination, may be altered indefinitely,
by merely changing the direction or the intensity of the light, all
the objects which give the figure remaining fixed in the object-box.
The optical arrangement by which these figures may be copied,
photographically, is substantially the same as that which is shown in
Fig. 52, where =C G D F= is the Kaleidoscope, =A O= the object-box,
and =L L= a small achromatic lens, of rock crystal or glass, a quarter
of an inch in diameter, placed in contact with the extremities of the
glass or metallic reflectors, and having its centre immediately behind
the small opening at =E=. When the rays of the sun, or any other strong
light, containing the actinic rays, are thrown obliquely upon the
object-box =A O=, an image of the Kaleidoscopic figure, produced by the
objects in the object-box, will be formed at =P P=, in the focus of the
lens =L L=. If the focal length of the lens =L L= is equal to one-half
=C G=, the length of the Kaleidoscope, the image will be formed behind
=L L=, at a distance equal to =C G=, and of the same size as the
object-box; but if the focal length of =L L= is greater than the half
of =C G=, the image will be formed at a greater distance than =C G=,
behind the lens, and the size of it will be greater than that of the
object-box, the distance and the size of the picture increasing as the
focal length of the lens increases; and when it becomes equal to =C G=,
the size and the distance of the picture will be infinitely great. When
the focal length of the lens is less than half =C G=, the figure will
be smaller than the object-box, and nearer the lens.
_The Kaleidoscope Camera._
Every camera employed for the purposes of photography may be readily
adapted for taking the pictures formed by the Kaleidoscope. We have
only to take out the lens or lenses which belong to it, and place the
Kaleidoscope furnished with its lens =L L=, Fig. 52, in the inner tube,
which is movable by means of the rack and pinion. If the picture can
be made distinct on the grey glass by the rack and pinion, a negative
or positive copy of it may be taken on collodion or paper, in the same
manner as other photographs. In some cameras the end of the box which
contains the grey glass is movable, backwards and forwards, so that the
adjustment for rendering the picture distinct may be effected, though
the Kaleidoscope is fixed in the front portion of the box.
When the camera is made for the express purpose of taking Kaleidoscope
pictures, it becomes a very simple instrument and may be constructed
easily and cheaply. It requires no lens excepting the small one =L
L= of rock crystal or of glass, a quarter of an inch in diameter.
The aperture required for this lens is so small that the spherical
and chromatic aberration cannot injure, in any sensible manner, the
distinctness of the picture. The difference between the chemical and
luminous focus, which cannot be made to coincide with a single lens,
may be easily determined by experiment, or in order to avoid this, the
small lens may be made achromatic.[16]
[16] A thin lens of rock crystal will transmit more of the actinic rays
than one rendered achromatic.
The form of the camera as fitted up with one of Mr. Bate’s
Kaleidoscopes, with metallic reflectors, is shown in the annexed
figure, where =M C D N= is the body of the camera, _m n o p_ the tube
which is moved out and in by a milled head attached to the pinion which
drives the rack on the tube _m n o p_. The Kaleidoscope =A B L L=,
exhibiting the figure which is to be copied, is temporarily fixed in
this tube by pieces of cork or wood, so that its axis, or the line of
junction of the reflectors, may be perpendicular to the surface of the
grey glass _p q_, which can be taken out, so as to allow the collodion
or paper slide to be placed in the same groove.
[Illustration: FIG. 53.]
The pictures should always be taken, when it is possible, by sunlight
incident obliquely upon the object-box, or with the illuminators
already described. When this cannot be done, artificial light,
containing the actinic or chemical rays, may be thrown upon the object,
as shown in Fig. 52. The light of coal gas, which may be condensed for
any length of time upon the objects in the object-box, will be found
to answer the purpose; but if a more rapid process is required, we
may, as proposed by Mr. Moule, use the Bengal lights, which contain a
large quantity of the actinic rays.[17] These lights are composed of
_six_ parts of _nitre_, _two_ of _sulphur_, and _one_ of _the sulphuret
of antimony_. The powder is made up in the shape of a cone, which is
ignited at the top; but it would be better to spread it out widely, in
order that it may be condensed upon the object-box. The lime-ball light
may also be employed, but the Bude light, which is a coal gas flame,
rendered more intensely luminous by a stream of oxygen, is preferable
to any other artificial flame. In using it, or any other of the lights
already mentioned, for obtaining Kaleidoscope figures, it must either
be placed very near the object-box, or condensed upon it by a large
lens, on account of the small size of the aperture at the eye-end of
the Kaleidoscope.
[17] See the _Journal of the Photographic Society_, vol. iv. p. 137.
In the formation of the Kaleidoscope figures, it is necessary to pay
particular attention to the colour of the objects of which they are to
be composed, _red_, _orange_, and _dark yellow_ objects, which transmit
few, if any, actinic rays, should not be employed. Blue glasses, which
transmit no red rays, are actinically more luminous than colourless
glasses, and therefore pale blue, pale green, and pale yellow glasses
may be advantageously combined with colourless glasses as objects for
the object-box.
When we wish to copy photographically the pictures obtained from
external objects, we must use the Telescopic Kaleidoscope of Mr. Bates,
by which the images of these objects are formed at the extremity of
the reflectors. These objects may be flowers, plants, architectural
ornaments, or parts of them, paintings, photographs, statues, or loose
and irregularly placed materials of any kind. In the figures created
by the common Kaleidoscope, we must trust to chance for the formation
of the figures, and can only choose those which we like out of a
large number accidentally formed; but when we make use of external
objects, we can group them and illuminate them in any manner we choose,
selecting those forms and colours which, when combined, produce the
effect that we desire.
This power, of arranging the objects, when in contact with the ends of
the reflectors, may be obtained with the Kaleidoscope of Mr. Bates,
shown in Fig. 29, by removing the anterior half of the cone when the
objects are opaque, and placing the camera in a vertical position.
The objects being placed upon a horizontal plate, may, if opaque, be
illuminated, by reflected light, and the picture of them, when combined
by the Kaleidoscope, taken in the same manner as when the instrument
was in the position shown in Fig. 52. If the figure is not what we
like, we can shift any individual object, or remove it, or replace it
by another, till we are satisfied with the combination.
The very same power of altering the combination, may be obtained
for transparent objects. We have only to place these objects on a
horizontal plate of glass, not connected with the Kaleidoscope, but
capable of being removed from it, and again brought close to the ends
of the reflectors. When the objects on the glass plate have been put
into their proper place, so as to give the desired picture, the plate
is brought as near as possible to the ends of the reflectors, and
the objects are illuminated either by solar or other light reflected
upwards upon the object-box.