a rich black tone, and of good quality. The whole secret of successful
bromide printing lies in correctness of exposure. It is generally taken
for granted that any poor, flat negative is good enough to yield a
bromide print, but this is not so. A negative of good printing quality
on printing-out paper will also yield a good print on bromide paper,
but considerable care and skill are necessary to obtain a good result
from a poor negative. The above developer will not keep in solution,
and should be freshly prepared as required. The same formula will also
be found useful for the development of lantern plates, but will only
yield black-toned slides.
«PLATINUM PAPERS:»
«General Instructions.»—To secure the most brilliant results the
sensitized paper, before, during, and after its exposure to light, must
be kept as dry as possible.
The paper is exposed to daylight, in the printing frame, for about
one-third of the time necessary for ordinary silver paper.
The print is then immersed in the developer for about 30 seconds, then
cleared in 3 acid baths containing 1 part of muriatic acid C. P. to 60
parts of water, washed for a short time in running water, the whole
operation of printing, clearing, and washing being complete in about
half an hour.
As a general rule all parts of the picture except the highest lights
should be visible when the exposure is complete.
When examining the prints in the printing frames, care should be taken
not to expose them unduly to light; for the degradation of the whites
of the paper due to slight action of light is not visible until after
development.
«Ansco Platinum Paper.»—Print until a trace of the detail _desired_ is
slightly visible in the high lights.
_Development._—Best results are obtained with the temperature of the
developer from 60° to 80° F. Immerse the print in the developer with a
quick sweeping motion to prevent air bells. Develop in artificial or
weak daylight. The development of a print from a normal negative will
require 40 seconds or more.
Formula for Developer.—
Water 50 ounces
Neutral oxalate of potash 8 ounces
Potassium phosphate (monobasic) 1 ounce
Care must be used to obtain the monobasic potassium phosphate.
Immediately after prints are developed, place them face down in the
first acid bath, composed of
Muriatic acid, C. P. 1 ounce
Water 60 ounces
After remaining in this bath for a period of about 5 minutes, transfer
to the second acid bath of the same strength. The prints should pass
through at least 3 and preferably 4 acid baths, to remove all traces of
iron that may remain in the pores of the paper.
When thoroughly cleared, the print should be washed from 10 to 20
minutes in running water. If running water is not available, several
changes of water in the tray will be necessary.
«“Water Tone” Platinum Paper.»—“Water tone” platinum paper is very
easily affected by moisture; it will, therefore, be noticed when
printing in warm, damp weather that the print will show quite a
tendency to print out black in the deep shadows. This must not be taken
into consideration, as the same amount of exposure is necessary as in
dry days.
Print by direct light (sunlight preferred) until the shadows are
clearly outlined in a deep canary color. At this stage the same detail
will be observed in the half tones that the finished print will show.
For developing, use plain water, heated to 120° F. (which will be as
hot as they can bear).
The development will be practically instantaneous, and care must be
taken to avoid air bubbles forming upon the surface of the prints.
Place prints, after developing, directly into a clearing bath of
muriatic acid, 1 drachm to 12 ounces of water, and let them remain in
this bath about 10 minutes, when they are ready for the final washing
of 15 minutes in running water, or 5 changes of about 3 minutes each.
Lay out between blotters to dry, and mount by attaching the corners.
«Bradley Platinum Paper.»—Developer.
A.—For black tones:
Neutral oxalate potassium 8 ounces
Potassium phosphate 1 ounce
Water 30 ounces
B.—For sepia tones:
Of above mixed solution 8 ounces
Saturated bichloride mercury solution 1 ounce
Citrate soda 5 grains
{530}
If deep red tones are desired add to B
Nitrate uranium 10 grains
Then filter and use as a developer.
«W. & C. Platinotype.»—Development.—The whole contents of the box of
the W. & C. developing salts must be dissolved at one time, as the
salts are mixed; and if this be not done, too large a proportion of one
of the ingredients may be used.
Development should be conducted in a feeble white light, similar to
that used when cutting up the paper, or by gas light.
It may take place immediately after the print is exposed, or at the end
of the day’s printing.
Develop by floating the print, exposed side downwards, on the
developing solution.
Development may take 30 seconds or more.
During the hot summer days it is not advisable to unduly delay the
development of exposed prints. If possible develop within 1 hour after
printing.
Either porcelain or agate—preferably porcelain—dishes are necessary to
hold the developing solution.
To clear the developed prints: These must be washed in a series of
baths (not less than three) of a weak solution of muriatic acid C. P.
This solution is made by mixing 1 part of acid in 60 parts of water.
As soon as the print has been removed from the developing dish it must
be immersed face downwards in the first bath of this acid, contained in
a porcelain dish, in which it should remain about 5 minutes; meanwhile
other prints follow until all are developed. The prints must then be
removed to a second acid bath for about 10 minutes; afterwards to the
third bath for about 15 minutes. While the prints remain in these acid
baths they should be moved so that the solution has free access to
their surfaces, but care should be taken not to abrade them by undue
friction.
Pure muriatic acid must be used.
If commercial muriatic acid be used, the prints will be discolored and
turn yellow.
For each batch of prints fresh acid baths must be used.
After the prints have passed through the acid baths they should be
well washed in three changes of water during about a half hour. It is
advisable to add a pinch of washing soda to the second washing water
to neutralize any acid remaining in the print. Do not use water that
contains iron, as it tends to turn paper yellow. Soft water is the best
for this purpose.
«W. & C. Sepia Paper.»—With a few exceptions the method of carrying
out the operations is the same as for the “black” kinds of platinotype
paper. The following points should be attended to:
The “sepia” paper is more easily affected by faint light, and,
therefore, increased care must be taken when printing.
To develop, add to each ounce of the developing solution 1 1/2
drachms of sepia solution supplied for this purpose, and proceed as
described for black paper.
The solution must be heated to a temperature of 150° to 160° F., to
obtain the greatest amount of brilliance and the warmest color, but
very good results can be obtained by using a cooler developer.
«Variations of the Sepia Developer.»—Primarily the object of the
sepia solution in the developer is to increase the brightness of the
prints, as, for example, when the negative is thin and flat, or dense
and flat, the addition of the sepia solution to the developer clears
up, to some extent, the flatness of the print by taking out traces
of the finer detail in the higher lights, which is often a decided
improvement. If, however, the negative be dense, with clear shadows,
the sepia solution may be discarded altogether. This will prevent the
loss of any of the finer detail and greatly reduce harshness in the
prints. Sometimes a half, or even a quarter, of the quantity of the
sepia solution recommended as an addition to the developer will be
sufficient, depending altogether upon the strength of the negatives.
Prints developed without the solution have less of the sepia quality
but are very agreeable nevertheless. It should be remembered that the
sepia paper is totally different from the black, and will develop sepia
tones on a developer to which no sepia solution has been added. The
sepia solution clears up and brightens the flat, muddy (to some extent,
not totally) effects from the thinner class of negatives.
«The Glycerine Process.»—The “glycerine process,” or the process of
developing platinotype prints by application of the developing agent
with the brush, is perhaps one of the most interesting and fascinating
of photographic processes, owing to its far-reaching possibilities.
{531}
By this method of developing platinotype paper, many negatives which
have been discarded on account of the dim, flat, non-contrasty results
which they yield, in the hands of one possessing a little artistic
skill, produce snappy, animated pictures. On the other hand, from the
sharp and hard negative, soft, sketchy effects may be secured.
There are required for this process: Some glass jars; some soft
brushes, varying from the fine spotter and the Japanese brush to the
1 1/2-inch duster, and several pieces of special blotting paper.
Manipulation.—Print the paper a trifle deeper than for the ordinary
method of developing. Place the print face up on a piece of clean
glass (should the print curl so that it is unmanageable, moisten the
glass with glycerine), and, with the broad camel’s-hair brush, thinly
coat the entire print with pure glycerine, blotting same off in 3
or 4 seconds; then recoat more thickly such portions as are desired
especially restrained, or the details partly or entirely eliminated.
Now brush or paint such portion of the print as is first desired with
solution of 1 part glycerine and 4 parts normal developer, blotting
the portion being developed from time to time to avoid developing too
far. Full strength developer (without glycerine) is employed where a
pronounced or deep shade is wanted.
When any part of the print has reached the full development desired,
blot that portion carefully with the blotter and coat with pure
glycerine.
A brown effect may be obtained by using saturated solution of mercury
in the developer (1 part mercury to 8 parts developer). By the use of
diluted mercury the “flesh tones” are produced in portraits, etc.
When print has reached complete development, place in hydrochloric
(muriatic) acid and wash as usual.
«Eastman’s Sepia Paper.»—This paper is about 3 times as rapid as blue
paper. It should be under rather than over printed, and is developed
by washing in plain water. After 2 or 3 changes of water fix 5 minutes
in a solution of hypo (1 1/2 grains to the ounce of water), and
afterwards wash thoroughly.
Short fixing gives red tones. Longer fixing produces a brown tone.
«Development of Platinum Prints.»—In the development of platinotype
prints by the hot bath process, distinctly warmer tones are obtained
by using a bath which has been several times heated, colder blacks
resulting from the use of a freshly prepared solution, and colder tones
still if the developing solution be faintly acidified. The repeated
heating of the solution of the neutral salt apparently has the effect
of rendering the bath slightly alkaline by the conversion of a minute
proportion of the oxalate into potassium carbonate. If this be the
case, it allows a little latitude in choice of tone which may be
useful. Some photographers recommend the use of potassium phosphate
with the neutral oxalate, stating that the solution should be rendered
acid by the addition of a small proportion of oxalic acid. When the
potassium phosphate was first recommended for this purpose, probably
the acid salt, KH_〈2〉PO_〈4〉, was intended, by the use of which cold
steely black tones were obtained. The use of the oxalic acid with the
ordinary phosphate K_〈2〉HPO_〈4〉, is probably intended to produce the
same result.
«THE CARBON PROCESS.»
The paper used is coated on one surface with a mixture of gelatin and
some pigment (the color of which depends upon the color the required
print is to be), and then allowed to dry. When required for printing it
is sensitized by floating upon a solution of bichromate of potassium,
and then again drying, in the dark this time. The process is based upon
the action of light upon this film of chromatized gelatin; wherever the
light reaches, the gelatin is rendered insoluble, even in hot water.
The paper is exposed in the usual way. But as the appearance of the
paper before and after printing is precisely the same, it is impossible
to tell when it is printed by examining the print. This is usually
accomplished by exposing a piece of gelatino-chloride paper under a
negative of about the same density, and placing it alongside of the
carbon print. When the gelatino-chloride paper is printed, the carbon
will be finished. The paper is then removed from the printing frame and
immersed in cold water, which removes a great deal of the bichromate of
potassium, and also makes the print lie out flat. It is then floated
on to what is known as a support, and pressed firmly upon it, face
downwards, and allowed to remain for 5 or 10 minutes. Then the support,
together with the print, is placed in hot water for a short time,
and when the gelatin commences to ooze out at the edges the print is
removed by stripping from the support, this process leaving the greater
quantity of the gelatin and pigment {532} upon the support. The gelatin
and pigment are then treated with hot water by running the hot water
over the face of the support by means of a sponge. This removes the
soluble gelatin, and leaves the gelatin, together with the pigment it
contains, which was acted upon by light; this then constitutes the
picture.
The reason for transferring the gelatin film is quite apparent, since
the greater portion of the unacted-upon gelatin will be at the back of
the film, and in order to get at it to remove it, it is necessary to
transfer it to a support. In this condition the print can be dried and
mounted, but on consideration it will be seen that the picture is in
a reversed position, that is to say, that the right-hand side of the
original has become the left, and vice versa.
If the picture be finished in this condition, it is said to have been
done by the single transfer method. In some instances this reversal
would be of no consequence, such as some portraits, but with views
which are known this would never do. In order to remedy this state
of affairs, the picture is transferred once more, by pressing, while
wet, upon another support, and allowed to dry upon it; when separated,
the picture remains upon the latter support, and is in its right
position. This is what is known as the double transfer method. When
the double transfer method is used, the first support consists of a
specially prepared support, which has been waxed in order to prevent
the pictures from adhering permanently to it; this is then known as a
temporary support. The paper upon which the print is finally received
is prepared with a coating of gelatin, and is known as the final
support.
«LANTERN SLIDES.»
The making of a good slide begins with the making of the negative, the
operations in both cases being closely allied, and he who has mastered
the first, which is the corner stone to all successful results in any
branch of photography, may well be expected to be able to make a good
lantern slide. A slide is judged not by what it appears to be when held
in the hand, but by its appearance when magnified two to five thousand
times on the screen, where a small defect in the slide will show up
as a gross fault. Patience and cleanliness are absolutely necessary.
The greatest caution should be observed to keep the lantern plates
free from dust, both before and after exposure and development, for
small pinholes and dust spots, hardly noticeable on the slide, assume
huge proportions on the screen and detract materially from the slide’s
beauty.
The high lights in a slide should, in rare cases only, be represented
by clear glass, and the shadows should always be transparent, even
in the deepest part. The balance between these extremes should be a
delicate gradation of tone from one to the other. The contrast between
the strongest high light and the deepest shadow should be enough to
give brilliancy without hardness and delicacy or softness without
being flat. This is controlled also, to some extent, by the subject
summer sunshine requiring a more vigorous rendering than hazy autumn
effects, and herein each individual must decide for himself what is
most necessary to give the correct portrayal of the subject. It is a
good idea to procure a slide, as near technically perfect as possible,
from some slide-making friend, or dealer, to use it as a standard, and
to make slide after slide from the same negative until a satisfactory
result is reached.
A black tone of good quality is usually satisfactory for most slides,
but it is very agreeable to see interspersed a variety of tone, and
beautiful slides can be made, where the subject warrants, in blue,
brown, purple, and even red and green, by varying the exposure and
development and by using gold or uranium toning baths and other
solutions for that purpose, the formulas and materials for which
are easily obtainable from the magazines and from stock dealers,
respectively.
It must be understood, however, that these toning solutions generally
act as intensifiers, and that if toning is contemplated, it should be
borne in mind at the time of developing the slide, so that it may not
finally appear too dense. Toning will improve otherwise weak slides,
but will not help under-exposed ones, as its tendency will be in
such case to increase the contrast, which in such slides is already
too great. Another method of getting a fine quality of slides is to
make rather strong exposures to over-develop, and then to reduce with
persulphate of ammonium.
The popular methods of making the exposure are: First, by contact
in the printing frame, just as prints are made on velox or other
developing paper, provided the subject on the negative is of the right
size for a lantern slide; and the other and better method is the camera
{533} method, by which the subject of any negative, large or small, or
any part thereof, can be reduced or enlarged, and thus brought to the
proper size desired for the slide. This is quite a knack, and should be
considered and studied by the slide maker very carefully.
Hard and inflexible rules cannot be laid down in this relation.
Portrait studies of bust or three-fourths figures or baby figures need
not be made for a larger opening than 1 1/2 by 2 inches, and often
appear to good advantage if made quite a bit smaller. Figure or group
compositions, with considerable background or accessories, may, of
course, have a larger opening to suit the particular circumstances.
Monuments, tall buildings, and the like should have the benefit of
the whole height of mat opening of 2 3/4 inches, and should be made
of a size to fill it out properly, providing, however, for sufficient
foreground and a proper sky line. Landscapes and marine views generally
can be made to fill out the full length of mat opening, which, however,
should not exceed 2 7/8 inches, and may be of any height to suit the
subject, up to 2 3/4 inches.
The subject should be well centered on the plate and the part intended
to be shown as the picture should be well within the size of the mat
opening decided upon, so that with a slight variation of the placing of
the mat no part of the picture will be cut off by the carrier in the
stereopticon. The horizon line in a landscape, and more particularly in
a marine view, should always be in proper position, either below or
above the center line of the slide, as may suit the subject, but should
never divide the picture in the middle and should not appear to be
running either up or down hill. And the vertical lines in the pictures
should not be leaning, but should run parallel with the side lines of
the mat; this refers especially to the vertical lines in architecture,
except, however, the Tower of Pisa and kindred subjects, which should
in every case be shown with their natural inclinations.
As to time of exposure, very little can be said. That varies with the
different makes of plates, with the quality of the light, and the
nature and density of each individual negative. Therefore every one
must be a judge unto himself and make as good a guess as he can for
the first trial from each negative and gauge further exposures from
the results thus obtained; but this much may be said, that a negative
strong in contrast should be given a long exposure, close to the light,
if artificial light is used, or in strong daylight, and developed with
a weak or very much diluted developer to make a soft slide with full
tone values. And a flat, weak negative will yield better results if
exposed farther from the light or to a weaker light, and developed by a
normal or more aggressive developer. Over exposure and under exposure
show the same results in slide plates as in negative plates, and the
treatment should be similar in both kinds of plates except that,
perhaps, in cases of under exposure of slide plates, the better plan
would be to cast them aside and make them over, as very little can be
done with them. For getting bright and clear effects it is now well
understood that better and more satisfactory results are obtained by
backing the slide plates as well as by backing negative plates. This is
accomplished by coating the back or glass side of the plate with the
following mixture:
Gum arabic 1/2 ounce
Caramel 1 ounce
Burnt sienna 2 ounces
Alcohol 2 ounces
Mix and apply with small sponge or wad of absorbent cotton.
It should coat thin and smooth and dry hard enough so it will not rub
off when handled. If the plates are put into a light-proof grooved
box as fast as backed, they can be used about half an hour after
being coated. Before developing, this backing should be removed; this
is best done by first wetting the film side of the plate under the
tap, which will prevent staining it, and then letting the water run
on the backing, and, with a little rubbing, it will disappear in a
few moments, when development may proceed. Other preparations for
this purpose, ready for use, may be found at the stock houses. The
mat should be carefully selected or cut of a size and shape to show
up the subject to best advantage, and should cover everything not
wanted in the picture. The opening should not exceed 2 3/4 x 2 7/8
inches in any case, and must not be ragged or fuzzy, but clean cut and
symmetrical. The lines of the opening of square mats should be parallel
with the outside lines of the plate. Oval, or round, or other variously
shaped mats, should be used sparingly, and in special cases only where
the nature of the subject will warrant their use.
Statuary shows up to best advantage when the background is blocked out.
{534} This is easily done with a small camel’s-hair artist’s brush and
opaque or india ink, in a retouching frame, a good eye and a steady
hand being the only additional requirements. This treatment may also be
applied to some flower studies and other botanical subjects.
Binding may be performed with the aid of a stationer’s spring clamp,
such as is used for holding papers together, and can be purchased for
10 cents. Cut the binding strips the length of the sides and ends of
the slide, and gum them on separately, rubbing them firmly in contact
with the glass with a piece of cloth or an old handkerchief, which
might be kept handy for that purpose, so that the binding may not
loosen or peel off after the slides are handled but half a dozen times.
Before storing the slides away for future use they should be properly
labeled and named. The name label should be affixed on the right end
of the face of the slide as you look at it in its proper position, and
should contain the maker’s name and the title of the slide. The thumb
label should be affixed to the lower left-hand corner of the face of
the slide, and may show the number of the slide.
«HOW TO UTILIZE WASTE MATERIAL.»