PHOTO PASTIMES
CAMERA KNIGHTS’ EXPERIMENTS
IT has been presumed in commencing these notes that most would-be
experimenters already possess a camera, or will at least shortly do so.
Thus the greater number of experiments are such as would interest a
camera fiend more deeply than the ordinary reader, although the latter
might still derive much enjoyment from conducting them so far as the
lack of a “dark box” will allow him.
It will perhaps be as well to spend a paragraph at the outset in
describing simply and noting a few peculiarities about the commonplace
camera. Photography means drawing by the agency of light. Now light is
reflected from an illuminated object in straight lines or rays, of which
a proportion may be collected by a lens and thrown in points upon a
surface behind. (See Fig. 1, A, illuminated object; B, lens; C, surface
behind lens; D, rays of light thrown upon surface C.)
[Illustration: FIG. 1.--Rays of light collected by lens and thrown upon
surface behind.]
The front of a camera contains the lens, and is provided with a movable
shutter, so that light may be only allowed to enter the dark box when a
picture is to be taken on one of the sensitive plates inside. According
to Fig. 2--which represents a camera in position to photograph the
object A--the light is reflected in rays, which are collected in myriads
of groups and cast pointed upon the surface of the sensitized plate B.
Such ray groups--being parallel when they leave the object and pointed
after passing the lens--are termed pencils of light, a most applicable
name when they are employed in “sketching” a portrait on the
photographic plate.
[Illustration: FIG. 2.--Camera in position to photograph object A.]
It will be seen that the action of the lens causes the base of the
object to be registered upon the top of the plate, and _vice
versa_--_i.e._ the picture is taken upside down. Another noticeable
feature about the magazine box camera, which does not, however, apply to
the focussing camera with bellows, is that it may not be placed nearer
than a certain distance (usually 10 feet or thereabouts) to the object
photographed, or else the picture obtained will be blurred. The
remembrance of this simple fact will save the loss of many plates to the
tyro.
Finally a last note remains to be taken of the “stops.” These are really
various sized holes in a metal screen, any one of which may be placed at
will before the lens, and by the use of which the sharpness or
distinctness of the photograph may be improved. Thus a lens at full
aperture will not give such a sharp picture as would be obtained if a
small hole were used, but, as the amount of light permitted to pass in
the latter case is much diminished, a longer exposure must be given.
Consequently when a short-timed snapshot is being secured, the largest
practicable aperture or stop should be employed, even though the
sharpness of the picture be thereby to some extent sacrificed.
Having thus briefly reviewed the essential features of a camera,
arrangements may be made for conducting our first experiment.
Experiment A.--A FIRESIDE PHOTO
Probably no souvenir can give greater pleasure to the amateur
photographer, or prove more acceptable to his bosom chums, than their
portrait, as a fireside group, lighted by the glow from a genial fire.
Nor is this difficult of attainment.
First the figures should be grouped seated on chairs--and perhaps some
standing behind, if many faces are to be included--in a quarter circle
from one chimney-corner, whilst the camera may be securely placed some 9
or 10 feet away, about the position shown at X in Fig. 3.
[Illustration: FIG. 3.--Relative positions of camera and sitters for a
fireside photo.]
Next some shade like a small fire-screen must be placed between the
blaze and the camera, in order to protect the sensitized plate from the
full glare of the firelight. Now of course the photograph is not
actually secured by the coal flame illumination, which would not be
bright enough to give proper exposure, so recourse is had to dropping
some material into the fire which will burn rapidly with a bright white
flame. Magnesium powder is generally used for this purpose.
Supposing the group to have been arranged and the camera firmly in
position, the person (B, in Fig. 3) seated next the grate should hold a
tablespoonful of saltpeter and also a square inch or so of sheet zinc.
Then, all being so far ready, let the outside member of the group
(marked A in Fig. 3) open the camera shutter and slip back to his seat,
whilst the flashlight operator drops the saltpeter and zinc successively
among the glowing coals. The flame of dazzling brilliancy which results
records the sitters’ figures on the plate, so that directly it is over,
the person (A) may again visit the camera and close the shutter. His
movements will not be noticeable, since they are made before and after
the flashlight.
The operation of development may be proceeded with at once and should go
fairly easily, but flashlight exposures are difficult to estimate
accurately, and therefore, although a square inch of zinc has sufficed
for a small group with stop and an extra rapid plate, this amount may
have to be increased if the group be large or if other conditions be
changed.
One last hint as to behavior of the sitters. Let them sit as naturally
and quietly as possible, but be advised to _blink their eyes as much as
the bright light prompts them_ rather than keep them staring wide open,
when their faces must wear a most inane expression in the finished
photo.
Experiments B.--“PHOTO-CHEMICAL”
Salts of silver form the basis of most modern photographic processes.
Thus in order to perform chemical experiments of a photographic nature,
some solution of silver must be available, the nitrate salt being
usually employed.
[Illustration: FIG. 4.--Silver solution and precipitate.]
It is best procured at the druggist’s in solution or as crystals, in
which latter case it must be dissolved for use in clean rain or
distilled water. The solution need be only weak, but must be kept in a
dark bottle screened from daylight. Chemical test-tubes, if they can be
obtained, will be found best for the experiments.
(1) Prepare a weak solution of table salt, and add it drop by drop to a
little of the silver nitrate in a test tube (or wine-glass as a
makeshift). A white sediment is precipitated, which, by shading part of
the tube with a band of paper and exposing to daylight, may be shown to
be sensitive to light, inasmuch as the unscreened part will rapidly turn
purple. This precipitate consists of silver chloride, which, in
combination with unaltered nitrate, forms the essential ingredient of
printing paper. In Fig. 4, A is Solution; B, Precipitate; C, Band of
Paper.
(2) Photographic plates are coated with bromide of silver, a yellow
substance, which may be prepared similarly to the previous precipitate
by adding potassium bromide solution (instead of table salt) to the
nitrate of silver. Its appearance does not change rapidly under the
influence of light, but if first exposed and then treated with a
developing solution the yellow color very soon changes to black--finely
divided metallic silver being, in fact, produced. Actually, light more
readily alters the constitution of the bromide than that of the white
chloride, but the former knows better how to preserve an outward
appearance of composure.
(3) Suppose, now, another solution be made, this time of the fixing salt
known familiarly to every camera knight as “Hypo.” When this is added to
either the white chloride or yellow bromide precipitates above noticed,
they gradually dissolve away, except such portions as have changed color
under the influence of light.
Such action constitutes the process of fixing a photograph, whereby the
sensitive silver compound is removed from those parts of the paper or
plate which have more or less escaped the influence of light.
(4) This experiment is an aquatic performance in which one actor
only--our old acquaintance Hypo--takes part. Provided proper care be
taken in the preparatory stages, it will afford at the climax as
excellent a spectacle as many another more complex.
[Illustration: FIG. 5.--Preparing saturated solution.]
[Illustration: FIG. 6.--Grooved cork for “dripping” solutions.]
A tumbler glass full of saturated solution has first to be prepared, and
this is best done by tying about ¹⁄₂ lb. of Hypo in a piece of muslin,
so that it may be held against the rim of the glass and allowed to hang
in hot water after the manner of Fig. 5. When an appreciable quantity of
the salt has dissolved, the liquid being but lukewarm, the muslin bag
may be removed and the solution stirred gently. Then it must be stood
somewhere firm, and allowed to remain absolutely undisturbed until cold.
There should then be a glass full of clear liquid, and the phenomenon is
at hand.
Let the smallest crystal of solid Hypo be dropped in this liquid, or let
it but be disturbed, and behold! a wonderful transformation proceeds,
until the glass interior becomes a shimmering mass of sparkling
crystals. The reason of this curious behavior is not far to seek. Hypo,
in common with most chemicals, dissolves to a greater extent in hot
water than in cold, but is different, inasmuch as the excess of salt
does not settle out as the solution becomes cold. Cold solution is
therefore really over-saturated, and to such an extent that only an
extra crystal or the least disturbance is sufficient to upset the
delicate balance, upon which climax the great excess of Hypo soon
settles out.
(5) This is another reaction in which Hypo takes part, but one other
substance is required as well, viz. permanganate of potash. Condy’s
fluid is equally suitable, and in either case the solution need only be
weak--just a transparent deep pink color. The vessel containing this
permanganate may be about half full. When Hypo solution is gradually
dripped into this and the mixture stirred, the color is immediately
dispelled, leaving the liquid clear as water.
Inasmuch as every photographer knows the necessity for washing his
prints until all fixing salt is removed, this decoloring action may be
fully employed in testing the washing water occasionally. When it no
longer affects the tint of a pink permanganate solution he may rest
assured that the deleterious Hypo--like some friends in being welcome so
they stop not too long--has really departed. For the ready performance
of this experiment it may be noted that any solution can most easily be
“dropped in drips” from a bottle whose cork is cut grooved at both sides
(Fig. 6).
[Illustration: FIG. 7.--Sensitizing blue-print paper.]
Experiment C.--BLUE PRINT PAPER
Engineers’ drawings have for many years past been copied upon
ferro-prussiate, or “blue print” paper. The original design being made
in opaque ink upon tracing linen, a sheet of the sensitive paper is held
against this in strong daylight until blue coloration has advanced
everywhere except beneath the ink lines of the drawing. These remain
yellow, or rather white, when finished, as the excess of sensitive salt
is removed by washing.
Since this last operation is in itself all-sufficient to insure
permanency, the simplicity is unique. In fact, the impossibilty of
securing other colors than blue has been the only factor to exclude this
process from far wider use.
The preparation of the sensitive surface presents no great difficulties,
provided a drawing-paper of good quality be used. It should be cut into
strips about 6 inches wide, which are passed one by one up and down (see
Fig. 7) through a dish containing the following solution: 1 oz.
ferri-cyanide of potash + 4 oz. water, added to 1 oz. ammonio-citrate of
iron + 4 oz. water. (_Note_--4 oz. water = nearly ¹⁄₄ pint.) This must
be done in very dull light--candle or paraffin oil by preference--and
the wet paper pinned up to dry in a dark cupboard, hanging from the edge
of a shelf or other projecting support. Then it may be cut into pieces
of the required size and stored with a wrapping of tissue and brown
paper in a handy box.
All manner of designs may be produced on this paper, such for example as
fern leaves, lace, and embroidery. Actual sea-view photos or imitation
moonlight views also look very well indeed. Another notion is to secure
the copy of some picture printed in black on thin paper, which has been
oiled and dried in order to render it translucent for quicker printing.
The final washings should be thorough, and then the blue print will last
its maker as long as the latter cares to keep it.
Experiment D.--TO SHOW THE CONSTITUENTS OF WHITE LIGHT
Few physicists to-day doubt that light consists of waves set up in an
all-pervading medium called ether; that, moreover, white light is
composed of different tinted rays--to be seen reflected from the bevel
edge of a looking-glass, or indeed from the more natural rainbow--which
further are caused by the different lengths of waves whereby the colored
lights are propagated.
Now we may produce these phenomena for ourselves by cutting a slit 1¹⁄₂
inches long in a temporary window-shutter, or, more conveniently, in the
end of a large wooden box (A, Fig. 8). Near this a glass prism, such as
once adorned gas-pendants so profusely, must be supported (B, Fig. 8) on
a block of wood, and at the opposite end of the box a sheet of paper
pinned to the inside (C, Fig. 8). The arrangement is shown in the
diagram.
Now notice, if you regard this screen from the open top--a large cloth
covering head and box in order to keep out superfluous light--a band of
color is depicted thereon, gradating gently like a rainbow from violet
through blue and yellow to red. Thus the white light which entered
through the slit has been separated into its component parts. So far,
gorgeous enough! But for the photographer much greater interest is at
hand, will he proceed as follows. Place the box so that bright sunshine
enters through the slit, and after fastening a piece of blue print paper
instead of the white on the box interior, allow this to print, at the
same time excluding extraneous light by a dark cloth overspread. When
this piece of paper has been washed and fixed, the colored band should
have registered itself in various shades of blue, from which it will be
noticeable that the purple and blue lights have darkened the paper most,
whilst red and yellow hardly affect it at all. If ordinary printing
paper, or still better, a photographic plate (in which latter case a
considerably shorter exposure will suffice, and outside light must be
rigorously excluded) be used, instead of the blue print paper, the
result is still more striking.
[Illustration: FIG. 8.--The refraction of white light into its
constituent colors.]
From this experiment further is to be gathered the reason for developing
plates by red light, which evidently does not affect the sensitive
surface in any appreciable degree. But, on the other hand, special
orthochromatic plates are made which, by dyeing, have been rendered
sensitive to the yellow rays as well as to the blue, and if one of these
be employed to “take” the colored band, technically called “spectrum,” a
totally different gradation is obtained compared with that on an
ordinary plate or on “blue print” paper.
Then again, suppose instead of sunlight, ordinary lamplight or
incandescent gas be used as an illuminant, the gradation varies, whilst
still another modification is to photograph the spectrum of a methylated
spirit-flame in which common salt is being burnt. In this case the light
is so yellow that an orthochromatic plate must be used. Another
illuminant worth testing is magnesium ribbon, which also may be ignited
in the spirit-flame.
Before saying a final adieu to these spectrum results, one last item
remains for remark--last but not least. We say that the series of
visible colors extended from violet through blue and yellow to red, and
that darkness obtained at each end. Well! Mount a plate or piece of
printing paper inside the box, so that half of it is well in the
darkness beyond the bluish-violet bands, and expose long enough to
secure a slight opacity in these parts (_i.e._ where the blue bands
fell) when the plate is developed and fixed. The half of the plate which
was in darkness and therefore apparently received no exposure,
nevertheless develops darker than the remainder, seeming to indicate
that some light, although invisible to the human eye, had affected the
sensitive silver compounds in the plate. This is actually the case. The
rays of light which exert this wonderful influence are called
“ultra-violet,” meaning beyond the violet, and their existence explains,
amongst other matters, why photography of the heavens has revealed the
presence of many thousands more stars than can ever be seen by man. Such
stars emit only “ultra violet” light.
Experiment E.--ONE PERSON IN TWO PLACES--AND SPIRITUALISM
Pictures of a man decapitating himself, or of the reader’s sister
turning the skipping-rope for another girl, who is herself, may justly
be called mystifying. Not only may they almost deceive the operator
himself, but will quite nonplus the uninitiated, to whom proofs may thus
be presented of the most impossible happenings. Two methods are
applicable to the production of such freak portraits, viz:--
(1) To photograph the entire picture in two separate halves on the
plate, moving the sitter from one position to another for each exposure.
(2) To employ a background as dark and dim as practicable, whilst
well-lighting the sitter and furniture, and giving a separate exposure
for each position of the model. The latter procedure is by far the
simpler, and provided reasonably correct exposures are given, success
should not be very elusive.
To take for a concrete example the portrait of a boy playing checkers
with himself. Hang up a curtain of black or deep-red material in some
dark recess of a room, and a few feet before it stand a small bamboo
table with checker-board, &c., complete, at which the person to be
photographed may be posed sitting. As mentioned above, all available
light must be concentrated on the group, whilst if the model be wearing
light clothes, the effect will be enhanced accordingly.
As to the camera, this may with greatest advantage be of the focussing
type, or at any rate a box instrument fitted with magnifiers, so that
by being placed near to the sitter the latter may be rendered large and
sharp in the portrait whilst the background remains indistinct. This
should be of such a size that its somber image well covers the whole
plate. A suggested arrangement for the tableau is sketched in Fig. 9.
The first exposure may be made with the person seated at 1--the
left-hand side of the table--he either resting one finger on a checker
as if about to make his move, or adopting such other pose as his acting
capabilities may suggest.
Primarily the time of exposure should be just sufficient for the
light-clothed sitter, and therefore not enough for the table and
background, which receive a second exposure. This should be made when
the model has taken his chair to the opposite side of the table, and
again assumed a position natural to the player, who anxiously watches
his opponent’s play.
[Illustration: FIG. 9.--One person in two places.
A. Table.
B. Black or red curtain as background.
C. Fireplace.
D. White sheet as reflector.
E. Camera.
1 and 2. Positions of sitter in first and second exposures.
]
All possible care must, of course, be taken to keep the table
undisturbed during the model’s movements, and also to insure that no
lighter object than the sitter himself has a place in either exposure
just where he appears in the other. For example, a pile of books must
not be photographed during the first exposure just behind or in front of
the position which the model is to occupy during the second exposure;
otherwise the vision of books through the person’s transparent chest, or
a similar incongruous phenomenon, will result.
SPIRIT PHOTOGRAPHY
Spirit or ghost photography is but a modification of these methods. The
chief element of success is to ignore the caution of the preceding
paragraph, and render the ghost figure as transparent as possible. The
first exposure should be an adequate one of the human model, who has
twisted himself into an attitude of groveling terror compatible with the
fright from which he is supposed to be suffering, whilst the background
behind him must be dark and indistinct, if he is next to impersonate
the spook. The latter’s surroundings, on the contrary, may be as
detailed and well-lighted as convenient, because the white-robed figure
is to appear transparent.
A sheet will be fit apparel for the “spirit,” and must be large enough
to drape entirely the gliding form with outspread arms.
The second exposure must be abnormally short, so as just to obtain a
faint impression of the sheet and its folds. Finally, if the
terror-stricken person can maintain his attitude of fear during the
first exposure, and also for the photograph of the ghost, whose rôle may
be taken by some one else beneath a sheet, there is no necessity to have
any part of the background unusually dark. Still, darkness is said to
favor spooks, so the background is perhaps entirely a matter of choice.
With such dash toward the borders of the spiritual realm, this series of
photo experiments must conclude. The most ardent camera fiend can
scarcely denounce them as embracing too narrow a field when he considers
that ghosts as well as mundane matters--psychical and physical
alike--have been approached. Even if his finger-tips do not resemble
ebony with silver nitrate, he may still rightly term his hobby the
“Black Art.” And his friends! Well, if present at the researches, may
their remarks be unheard. Doubtless they will ponder deeply, and
conclude that the camera does sometimes lie.
* * * * *
Sun pictures of the earliest types had been no long time in existence
before a rumor spread that photography could not lie. Critics and
admirers of the new process rightly enough concluded that a knight of
the camera must be constrained to narrow interpretations by his
instruments as no artist is by his brushes. But this conclusion, held
widely now as then, is only in part correct. The camera records the
relative position of objects absolutely, but may on the other hand
ruthlessly destroy all sense of perspective, or render globular images
of rectilinear buildings. Nor are these the only peculiarities which, in
themselves disadvantageous, may frequently be turned to account by the
photographer.
Sensitive plates are seldom correctly exposed. They either suffer under-
or over-exposure, and when there is a gross error the resulting picture
either lacks detail and is blotchy, or else presents the light gradation
of a London fog. But, as a set-off to these failings, it might be noted
that moonlight pictures are obtainable by excessively short daylight
exposures, which give only the outline of the objects, and a contrast
between light and shade appropriate to night scenes, whilst photographs
of flowers, portraits, and cloud studies may mostly receive full
exposure with advantage, the softness of lighting engendered lending
additional charm to such subjects.
[Illustration: FIG. 10.--Slanting screen (C) with circular aperture to
equalize exposures of sky (A) and foreground (B) in landscapes.]
Landscapes commonly reveal over-exposure of the sky or inadequate
exposure of the ground and objects, because the amounts of light emitted
by these respective portions differ so much. To obviate this difficulty
an early photograph worker devised, and indeed used, the arrangement of
a circular aperture before the lens, slanting so that it might not admit
such large parallels of light from the sky as from the ground portion.
The device is more easily understood from the accompanying sketch (Fig.
10).
[Illustration: FIG. 11.--A method of securing “modeling” in
portraiture.]
The portrait hunter should rejoice to realize that, by judicious
procedure, persons of the coarsest complexion may be flattered in their
likenesses. Not the least valuable dodge is to render freckles and red
blotches invisible by the use of orthochromatic plates, and, if
necessary, a yellow screen, which articles prevent the pink skin from
securing any advantage over the insular blotches in point of actinic
light value.
A supplementary method of securing pleasant portrait effects is to mount
a disc of cardboard (A, Fig. 11), round whose edge holes of various
sizes from ¹⁄₄ to ⁵⁄₈-inch diameter and about ¹⁄₂-inch apart are cut (B,
Fig. 11), in front of the camera on a spindle (C, Fig. 11) as shown. Any
one of the holes should be adjustable exactly in front of the lens, and
the mode of usage is to spin the card disc rapidly whilst the exposure
is being given. This should, of course, be proportionately longer than
usual.
NOVEL RESULTS
Excellent imitations of crayon pictures are to be produced by taking the
required photograph through a negative screen, which has been made by
copying to equal size or slight reduction, a piece of rough
drawing-paper rubbed evenly with charcoal. It is employable in two ways,
either by keeping it in contact with the sensitive plate in the dark
slide whilst the photograph is being taken--a slightly longer exposure
being given--or else holding it in the frame on the opposite side of the
negative to the sensitive paper during printing, which is conducted in
the sunshine.
By systems of double or triple printing, all manner of novel results are
obtainable. The only difficulty presented in this work is that of
correct registration, but if printing paper--the most usual medium--be
employed, this should not be insurmountable even at the first trial. As
a first instance of these compositions, suppose out of black paper 4
inches by 6 inches, a piece be removed the shape of the negative portion
required, and this mask be used to print through on to a sensitized
postcard. The black shape removed should have been gummed on to tissue
paper and this used, after the picture portion has been secured, to
print a border--showing the grain of the translucent paper--around the
photograph.
For a second, and last, example of triple printing, proceed by first
preparing the negative of a picture frame, in which, however, an
ordinary plain canvas surface has superseded the work of art. The idea
is then, by multiple printing, to introduce a camera view into this
frame image, and so make the result resemble the copy of another
painting.
Cut a black paper mask with an aperture the exact size of the canvas
image in the frame negative, and through this mask print the photograph
required a shade lighter than usual. Then substitute the frame negative,
and, with the same mask in place, secure a slight record of the inner
canvas image over the photograph already printed. This gives the
requisite oil painting effect. Lastly the piece of black paper,
originally removed to form the mask, is fixed over the canvas image of
the frame negative and the sensitive paper replaced in position, so that
registration and printing of the frame periphery is secured. Then toning
and fixing ensue, and the “fraud” is complete.
[Illustration: FIG. 1.--Plan of Marionette stage.]