DEVELOPMENT.
[Sidenote: Study of chemistry.]
Before entering on the subject of development, it is necessary to tell
the student that if he does not already understand the principles of
chemistry, he should lose no time in doing so, and as aids to such
understanding he cannot do better than get Roscoe’s “Lessons in
Elementary Chemistry,”[12] and Abney’s “Photography with Emulsions,” and
master the chapters mentioned in the footnote, ignoring the rest for the
time. Also let him buy Bloxham’s “Laboratory Teaching.” For a few
shillings he can purchase apparatus enough to do qualitative analysis.
This he will be able to do by following Mr. Bloxham’s directions,
omitting, perhaps, testing with the blow-pipe. If he has the time and
means, he will do well to do some quantitative analysis, working, say
with water, since it is of such immense importance to the photographer.
He will find a knowledge of chemistry as interesting as useful, and the
power of observation and accuracy acquired by the study will be
invaluable in subsequent stages of his work. We refer the student to
works on chemistry by specialists, because we think it is a mistake to
swell the bulk of our book by an exposition of chemical principles. We
caution the student, however, who intends to take up photography as an
art, to have nothing to do with plate-making. [Sidenote: Plate-making.]
That manufacture can only be done satisfactorily by experts constantly
employed at it, and it is as reasonable to expect a painter to prepare
his own colours, and make his own canvas, as to insist upon a
photographer making his own plates. Some people have tried to propagate
the false idea that a picture taken on a plate of the exhibitor’s own
making has a special kind of merit, but obviously this is only true when
the object is an “Emulsion process competition.” In judging of the
merits of a picture, no facts should be taken into consideration, save
the art expressed by the picture. [Sidenote: Plates.] Still the student
should know the methods by which his plates are prepared, and that his
chemistry will teach him, and when he has found plates which suit him,
let him keep to them. We have worked with fourteen different kinds of
plates, and have found most of them good, though each requires different
treatment. One piece of advice is, however, necessary, always buy your
plates direct from the makers, unless you can rely upon your dealer.
Some plates are, of course, much quicker than others, and this point the
beginner must carefully bear in mind, making his exposures accordingly.
[Sidenote: Vigilance committees.] He must not forget, however, that
there are brands of plates which are “starved” of silver; these he
should avoid, and it would be well if a vigilance committee were
appointed in every society to test batches of plates occasionally, and
report on them in the photographic journals, thus showing up the
fraudulent manufacturers. Assuming, then, that the student has carefully
studied the chemistry of development and has fixed on a satisfactory
brand of plates, we will proceed to give him a few practical hints, but
before we do so we must get rid of an obstacle in his path, and that is
the wet-plate process.
-----
Footnote 12:
Roscoe’s Chemistry:—
Lessons 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17,
18, and potassium, sodium, and ammonium in lessons 19, 22, 23;
chromium and uranium in lesson 25; mercury, silver, and platinum
in lessons 26, 27, and 28.
“Photography with Emulsions:”— Caps. 1, 2, 3, 5, 6, 7, 8, 9, 22,
24, and 31.
-----
[Sidenote: Wet-plate process.]
If the student were to ask ten middle-aged photographers whether they
prefer a wet plate or a dry plate negative, nine out of ten would, without
doubt answer, “Oh, a wet-plate negative.” If the student is curious and
asks, why? he will get a vague answer, in which the words “bloom” and
“beauty” play conspicuous parts, the adjectives reminding him of an
advertisement for patent balms for the skin. The fact is, not knowing the
first principles of art, photographers have raised for themselves false
gods, and they are still worshipping them. Let us at once and most
emphatically state that wet plate negatives do not give so true an
impression of nature as a gelatino-bromide plate, nor are the results so
artistic. We have seen much of the best of Mrs. Cameron’s work, and she
obtained from collodion and silver some of the best results ever obtained
from wet plates, for she had artistic insight, yet even in her work the
tonality is not so true, and the “quality” and freshness is not so fine as
can be obtained from gelatino-bromide negatives. The work by this process
is hard, and incapable of expressing texture correctly, while the general
impression is more or less artificial. This is fortunate for us, for the
slowness of the wet-plate process would seriously handicap it, even if the
artistic result were better than that of dry plates. The inadequacy of
collodion plates is emphasized when we look at the work of the craftsmen
who used them, and whose ideal was sharpness and “bloom.” Such work will
be found most unnatural and inartistic. Surely many of the false ideas
current amongst photographers arose from the evolution of the art.
Daguerreotypes, the first photographs, were shiny, and most of the
subsequent processes followed in their wake, until one clear-sighted
photographer, Blanquart-Evrard, tried to combat the evil tendencies.
Considering, then, the poor artistic quality of collodion plates and their
slowness in exposure, there is absolutely nothing to be said in their
favour for art work. It is decided, then, that our student will work with
gelatino-bromide plates.
[Sidenote: Hints to be remembered in developing.]
We venture to state briefly certain hints founded on the chemistry and
practice of development, which the student must have at his fingers' ends,
for let him remember that _the vital question of tone depends on
development_. That exceedingly nice question of getting the tones in
approximately true relation, which gives all artists so much work, gives
him who uses photography as his medium no less thought, and it is on
account of the _plasticity of the process of development_ that we can at
once take our stand and repudiate the ignorant assertion that photography
is a mechanical process. Of course there are fifty other reasons why it is
not merely a mechanical process, to mention one more of which will be
enough, i.e. the variety of exposures ranging between the 1/2000 of a
second (as with Muybridge’s work), and a couple of hours as in taking an
interior. Developing is really what modelling is to the sculptor, and as
art guides the modeller’s hand, so it must the photographer’s who wishes
to obtain _pictures_, and the art value of the work of both men will be
proportionate to the art knowledge and insight of the workers. Now you can
understand how absolutely necessary to pictorial photography is a
knowledge of art. Where photographers are devoid of all art knowledge,
their aim is to get “pluck,” “nice gradation,” “vim,” “snap,” “sparkle,”
“brilliancy,” to use only a few of their strange and cheap terms, and,
according to them all these loosely named qualities must be present
equally in a sunny picture and in a grey day picture, if ever they dare to
expose a plate on a grey day. It is all such talk that has brought
photography down to be called a merely mechanical process, which of course
it becomes in the hands of those who can and do give “pluck” and “sparkle”
to every negative, regardless of effect. It never occurs to these that
each picture is a problem in itself, and needs different management from
beginning to end. They aim for their “sparkle” from the moment of exposure
to the end of development, and obtain all the other qualities described so
eloquently by their cheap adjectives, by their _unvarying_ development.
Now let the student, keeping all this in mind, carefully commit to memory
these hints, for they are of vital importance.
[Sidenote: Hints.]
Placing the plate in water before using the developer is equivalent to
weakening the developer.
By first immersing the plate in the pyrogallic acid solution with no
restrainer or alkali, the subsequent development is slowed, and greater
contrast obtained. When pyrogallic acid is added in excess, too great
density and fog result. By adding pyrogallic acid, greater density and
contrast are obtained.
If the high lights are getting too dense, before the detail in the shadows
is well out, take the plate out of the developer and let the details
develop up with the amount of solution contained in the film, and then
replace it in the developer for density, if necessary.
Develop plates coated with quick emulsions to a greater density than
others.
Where there is much black and white in the picture, as in photographing
sculpture against black velvet, weaken the pyrogallic acid. The alkali
brings up the detail, and in properly exposed pictures increases density.
In excess it causes fog. The rate at which the picture is to be developed
can be governed by the restrainer, which also checks detail and increases
density. For long exposures the restrainer should be freely used, whilst
for quick-exposure work its use should be very limited.
Too much hyposulphite in the developer tends to solarization. Although its
value in the alkaline developer has been denied, we are of opinion that in
certain cases it is invaluable; it accelerates development in dark
shadows, rendering the reflected light in the shadows as nothing else can.
Captain Abney recommends its use in the ferrous oxalate developer only,
but we are well assured of its value in conjunction with the alkaline
developer in all cases of very rapid exposure.
The action of the developer is of course increased by the alkali, and
slowed by the oxidizing agent, but the tonality is affected unless it be
well governed by the restrainer.
If a picture flashes out quickly, add the restrainer and plenty of water.
If it comes up very slowly, mix a new developer containing half as much
restrainer as the normal and twice as much alkali.
The quicker the action of the developer the less marked the relative
tones; this is most important to remember; the pyrogallic acid should
never be extremely strong, never perhaps so strong as recommended in the
standard formulæ. [Sidenote: Method.] We must remember, then, that we have
our three necessary factors for development, the oxidizer, the alkali, and
the restrainer, all of which we can modify at will. On our minds, too, we
have, or should have, a vivid impression of the picture translated into
black and white; we remember what we wish to emphasize, and what to
subdue, so that the resulting picture shall be true in tone and
impression. We proceed then to mix our developer accordingly, remembering
first that the temperature of the developing-room makes a difference, and
remembering that the photographic image exists on the film to a degree
proportionate to the actinic value of the light which fell upon it.
Therefore, if it is a brightly-lighted landscape in sunshine, taken with a
full exposure, we must get a picture in a high key, but be it remembered
in such a picture the light greys will be lost in the whites, as has been
already shown; on the other hand, if it is a very low-toned effect, the
dull greys will be lost in the blacks. [Sidenote: Slow development.] We
must never forget to develop _all plates slowly_, let this be our
ever-present rule, for by developing slowly, the student has far more
command over his work, and that is what every artist seeks. No haphazard
work, but complete control, so that we can mould the picture according to
our will. And here we must again remind the student that he can never get
scientifically correct gradations from high light to deep shadow,
therefore he must be prepared to get only the true impression, and as a
fundamental law, let him remember to _watch over the truth of the lowest
tones_.
[Sidenote: Meteorological conditions to be adhered to in developing.]
It must not be forgotten that Nature is ever varying, and that the
chemicals will act differently under different conditions of temperature,
mixture, electrical conditions, &c., &c., and the worker must learn to
modify them accordingly; thus weaker solutions should be used in summer
and on mist effects. In fact, the more one sees into photography, the more
difficult does the matter become, for every picture is, from start to
finish, a new problem. Artistic work is not nearly so amenable to rules as
is laboratory work, where the conditions are generally more constant and
better determined. Even the state of the weather at the time of exposure
has great influence. The careful observer will soon see, in going over a
collection of first-rate negatives, developed by the same hand and
developer, that they all differ in quality, each one has physical
characteristics of its own, which are the combined resultant of these
protean conditions of Nature, and that such is the case is yet another
proof of the individuality of a photograph _per se_, apart from any other
reasons.
[Sidenote: Plates to be developed on day of exposure.]
Another very important point is the fact that the light does not act on
the film proportionately to the length of exposure; the greatest action
occurs at the earliest part of the exposure, as can be proved, in a rough
way, by exposing a plate on different subjects for the same length of
time. This fact alone at once and obviously creates a fatal objection to
composite photography. It is a fact which must be constantly remembered in
relation to tonality. It has been stated that an under-exposed plate can
be improved by being kept (undeveloped) for several months, the idea being
that the action having once begun will continue, but this is not our
experience with gelatine plates, though we have observed something of the
kind in working with carbon tissues. Instead of keeping his exposed
plates, our advice to the student is _develop your negatives as soon as
possible after exposure, never later than the day on which they are
taken_, and for these reasons. First, and chiefly, because you should
develop your negative whilst yet the mental impression of what you are
trying for is fresh. You have, we will hope, analyzed your subject and
thought it all out in black and white masses, and by developing while that
analysis is still vivid to you, you stand a very much greater chance of
getting a true thing. Secondly, of course, you are on the spot to take
another negative if the first prove a failure. For complete success, this
is the only way, and even if it entail carrying about a cumbersome dark
tent, the practice will in the end bring its own reward, and it must be
insisted upon as the best method of working. The astounding habit which
some industrial photographers indulge in, of sending their operators all
over the country, while they themselves stay at home to develop the work
of those and other operators, accounts in a great measure for the numerous
parodies of Nature which deck the shop-windows. This is truly mechanical
work, and we are prepared to say that no one, save by mere chance, can
produce perfect artistic work, _who does not develop his own plates on the
spot_. [Sidenote: On over-production.] Then, again, the student of
photography who wishes to produce artistic work must not hurry or
over-produce. One _picture_ produced in a month would be well worth the
time and trouble spent on it. We once asked an eminent landscape painter
how many plates he would be content to produce in a year if he were a
photographer. His answer was, “Twenty first-rate things would be good,”
and _that meant working all the year round_. We recommend that saying as
one worthy to be remembered. The poet Gray purchased immortality by one
short poem; many historians and novelists, now forgotten, have written as
many volumes as there were verses in that one poem of Gray’s, yet few
would prefer the oblivion of the prolific ones to the name that Gray has
won.
[Sidenote: Ferrous oxalate developer.]
But we must go back to developing, and we come now to the question of,
“What developer to use?” In our opinion the ferrous oxalate developer is
unsuited to artistic work. At one time we used it for negatives and
positives. For negatives we do not think it gives the quality which can be
obtained with the alkaline developer nor does it allow of the same
control, which is, of course, a very grave fault. For positives, on the
other hand, where the conditions are better known, and where absolute
purity of film is required, it is very useful, but as we are not concerned
with positives here, we will not go further into the matter.
[Sidenote: Chemicals.]
We must impress upon the student the necessity of always using fresh and
pure chemicals, and to secure such, it is wise to procure them from a good
chemist.
Re-sublimated pyrogallic acid should always be used, and re-crystallized
_sulphite_ of soda, and, above all, be sure the water is pure. For all
operations where chemical action results, none but pure non-aerated water
should be used, preferably, boiled, distilled water, for the air and other
impurities in ordinary water may be most harmful, as any one who has
studied the analysis of water and air knows well.
Let the developers (the stock solutions) be mixed with boiling or
distilled water, for this will aid in preserving them. The alum and
hyposulphite solutions should be mixed with cold boiled distilled water,
the alum bath being a saturated solution.
[Sidenote: Standard developer.]
Perhaps the simplest advice we can give as to the particular developer to
be used is to take as the normal developer one mixed according to the
formula sent out with the plates which the student has chosen to work
with, but the student must not use it in the exact proportions given by
the maker. Let the student mix up the stock solutions as told, varying the
constituents as the case in hand demands. If he has carefully and
thoroughly read his chemistry, and if he remembers the hints we have given
him, he will have no difficulty in following out the directions.
He should, as a rule, never use more than two-thirds of the amount of
pyrogallic acid recommended; let him be very careful how he uses the
restrainer, and let him add the ammonia _only in small quantities_, unless
the exposure has been very rapid. As a rule let him work with _weak
developers_. We could easily give a dozen or even fifty formulæ for
developers, but the student would be no wiser if we did, only more
confused. Every photographer fancies his own particular formula, but we
have no belief in any special favourites; we have worked with many, and
find the results depend altogether on the quantities used and the manner
of developing rather than on the constituents. Take, then, the formula
recommended by your plate-maker, but use it, as we have said, with
judgment. Begin with a sufficiency of pyrogallic acid (according to the
subject), use little restrainer, except in over-exposure, and add the
ammonia slowly, adding a few drops from time to time as required. In
short, make it your rule to _use weak developers, and develop slowly_. If
you think you are likely to have under-exposed, add ten to twenty drops of
a one per cent. solution of hyposulphite of soda, using no restrainer.
Some unscientific persons imagine that development can be reduced to a
science, and that absolute quantities of each solution must be used. One
might as well expect a physician always to prescribe the same doses. Each
picture requires a developer of its own; that should never be forgotten.
We have tried hydrokinone instead of pyrogallic acid; a given quantity of
hydrokinone does the work of double that quantity of pyrogallic acid, but
it has no advantages, so far as we can see, except for the development of
under-exposed plates. For very rapid work we recommend the
carbonate-of-potash developer, as green fog does not result. [Sidenote:
Eder’s potash developer.]The formula we use is Dr. Eder’s:—
A. ℞ Pure dry mono-carbonate of potash 90 parts
Water 200 ”
B. Pyrogallic acid 12 ”
Sulphite of soda 25 ”
Citric acid 1½ ”
Water 100 ”
Before using, mix forty to sixty drops of A with three ounces of water,
and the same quantity of B. We generally use more water than that
recommended in the formula.
Now it will be remembered that in bright sunny effects brilliancy, and
therefore density, is needed; the gamut of light and shade is not so
extended as in some subjects, for the shadows are bright with reflected
light, but the whole must be brilliant and in a high key. In our opinion
Dr. Eder’s potash developer gives this better than any other. For snow
scenes, on the other hand, where there are often very black heavy shadows,
we recommend, as we have done before, the developer given by the maker of
the plates, used in a weak solution.
[Sidenote: Local development.]
No photographer need hope to obtain perfect results and exactly what he
wishes, without resorting to local treatment; and here once more the
knowledge of the artist steps in and places him at an advantage over the
craftsman, but no one without sound art-knowledge should attempt this
local development. On the other hand, with a thorough knowledge of the
tonality of his subject, the artist can, by local development, so modify
his work that he will be able to obtain wonderfully true results. Let us
imagine such a subject as a dark tree in the foreground of a landscape
with a bright delicate distance. No manner of development will bring these
into true relation unless local treatment is resorted to. Unfortunately,
directions cannot be given for this work, for each subject will of course
require special treatment; the rationale of the practice, however, is
founded on the general chemical principles of photography. For use in
local development, then, it is always wise to keep a series of small
paint-brushes at hand. All three developers may thus be used locally with
great effect. During local development, the plate should constantly be
re-plunged into the developer, so that the local development may not show.
We strongly recommend the student _always to develop by artificial light_,
for by this method he will have a more regular standard to judge of the
quality of his negative than if he trusts to the varying strength of
daylight.
The best way of judging of the tonality of a negative is to hold it up
from time to time before the light of the developing-room; correct
judgment on this matter can, however, only be obtained by long experience.
The student will be told in the printed directions—supplied with many
plates—that if the image does not come up in 10 or 15 seconds, the plate
has been under-exposed. This is not our experience, and, as a rule, the
image takes longer to show than the time named. We prefer to judge by the
way the image comes up. If the highest lights come up very sharply defined
and turgid, then the plate is under-exposed, but if they come up
delicately, and detail begins to appear gradually over the various parts
of the plate, all is well. But all this will only become familiar by
experience. By constant habit the student will mentally run over the facts
of the problem before him, as does a physician, and proportionately to his
skill will he apply the right remedy at the right time.
[Sidenote: After treatment of plate.]
After development the plate should be well washed, and then placed in an
alum bath. Alum acts as a scavenger, and clears up all the remains of the
developer. Next the plate should again _be well washed_, and put in the
hyposulphite bath. This bath should be constantly renewed, for as soon as
it becomes well discoloured it is inadvisable to continue its use. It
should not be made stronger than 1 to 5, 1 to 10 being the best
proportion. Taking the plate from the fixing bath, you should wash it very
thoroughly, and re-plunge it into a fresh alum bath, leaving it for a few
minutes, then again wash it, and put it into a plate-washer, the water of
which should be frequently changed. It can then be placed in a drying
rack, and left to dry gradually in a dry room, where no dust is raised.
[Sidenote: Duplicate plates.]
It is, in our opinion, always well to expose two plates on each subject,
for the operator can thus, in a second plate, correct any error he may
detect in the first. This is our own invariable rule, and the practice,
apart from the better results obtained, has taught us better than any
other method could have done, how wonderfully the plate can be brought
under the operator’s will. It is hardly necessary to say the first plate
should be examined after development, by daylight, before proceeding to
develop the second. Once having seen a beautiful thing in nature, the
enthusiastic student will determine to get it _perfectly_, if it takes
fifty plates and as many days to do it in.
[Sidenote: Study of tone.]
We strongly advise those desirous of doing artistic work to begin by
studying tone, expose (always giving two exposures to each subject) on
selected subjects, especially fit for the study of tone; for example, a
figure in a white dress against a white background, another in a black
dress against a black background, and then a white dress against a black
background, and a black dress against a white background; some white
flowers against a sheet of white paper; yacht-sails against the sky; faces
against the sky; black velvet in bright sunshine, and on a grey day;
yellow flowers (with orthochromatic plates) on a white background. In
short, the student should think of all the possible harmonies and discords
that can be found indoors and out of doors, and he should, before taking a
plate, make a mental translation of the subject into black and white, and
put on paper roughly, with a piece of charcoal, what he expects to get, by
drawing rough masses in tone of the subject. He should at first think
nothing whatever of composition, or the more poetical qualities of a
picture; but simply study tone, and by this he will learn thoroughly
exposures and development. Let him eschew all requests to take portraits,
dogs, horses, parks, and what-nots; but let him always study tone. When he
has mastered tone, and with it exposure and development, he knows the most
difficult part of his technique and practice, let him then proceed to
picture-making. In this early stage let him take anything and everything
that is a study of tone, and let him take it anyhow, no posing, no
arrangement, and when he knows his _métier_ thoroughly let him destroy all
these early plates ruthlessly. We strongly advise him to give away no
prints of early work, or he will most surely rue the day when he did so.
In our opinion a year is not too much in which to work in this way, both
in doors and out of doors, in studios and out, with shutter and without,
before there is any attempt to take a portrait or picture of any kind.
[Sidenote: Accidents and faults.]
In working with gelatine plates various unavoidable accidents and faults
will crop up, some of which can, however, be remedied. Such cases we will
now go into.
[Sidenote: Under-exposure.]
Gives chalky whites and sooty blacks, _ergo_ no tonality, _ergo_
worthless. No remedy, destroy at once.
[Sidenote: Over-exposure.]
Gives thin negatives. What a thin negative is, is a matter of opinion, and
must be settled by a comparison of the print with the impression of nature
which it is wished to obtain. For many effects thin negatives are
invaluable, and the student must not take the ordinary photographer’s
opinion as to his negatives; but only that of an artist, for, as has been
shown, low-toned prints are unrecognized by the ordinary craftsman, his
aim and object is never to produce such things, these he designates by all
sorts of names, whereas they may be, by their tonality, infinitely truer
than his “sparkling” falsehoods. In short, it all depends on what the
student wishes to express. Some of the best work done has been produced
from negatives made purposely thin, which have at the same time been true
in tone, and full of breadth. [Sidenote: Intensification.] The density of
a negative can be increased by intensifying the negative; but it must not
be forgotten that intensification does not, in our opinion, correct the
_tonality_, this is a matter of great importance which has been
overlooked. From this it will be seen that a negative that requires
intensification is worthless for artistic purposes, and had better be
destroyed at once. But as intensification may be required for some
particular object, we must caution the student against the ordinary
perchloride of mercury and ammonia intensifier. In many cases it acts well
enough, in many others it acts unevenly and in patches, and in all cases
it is not permanent. The best intensifier we know of is Dr. Eder’s, whose
formula we give—
[Sidenote: Dr. Eder’s intensifier.]
℞ Uranium nitrate 15 grs.
Potassium ferricyanide 15 grs.
Water 4 ℥
Wash the plate thoroughly after fixing, so that no hyposulphite remains,
and immerse in the intensifier. It works up the scale from the lower
tones, which is an advantage over any other. To remove all the
hyposulphite of soda it is well to treat the plate before using the
intensifier, as Captain Abney directs. A drachm of a 20-vol. solution of
peroxide of hydrogen should be mixed with 5 oz. of water, and the plate
soaked in it for half an hour, and then washed.
[Sidenote: Fog.]
The student will find that for certain effects he may intentionally
produce a slight fog over his plate, as has often been done with very good
results; but if his plates are unintentionally fogged, they are ruined.
Fog is due to light having had access to the plate, either during
manufacture, during exposure, or during development. By developing an
unexposed plate it can be proved whether it was fogged during the
manufacture, as in that case the plate turns black. If the fog is caused
by a leaky camera the edges of the plate, which are generally clear glass,
are not fogged, for they have been hidden behind the rebate of the dark
slide. Light coming through the dark slide shows itself in lines or
patches, and is not general. If all these sources have been eliminated,
the dark room must be suspected. This is tested by putting a plate in the
slide, drawing the shutter out half way, and exposing the plate for a few
minutes to the developing light. If the exposed half fogs, then the dark
room is to blame.
[Sidenote: Red fog.]
We have only met with this phenomenon once, and that was in developing a
uranium plate. [Sidenote: Green fog.] This is green by reflected light,
and red by transmitted light. It is generally deposited at the corners of
the plate and round the edge.
[Sidenote: Yellow and brown fogs.]
Are rarely met with, and are yellow and brown by _reflected_ light,
whereas stains are coloured only by transmitted light. The student can
easily distinguish between fogs and stains in this way. We have been very
successful experimentally with Captain Abney’s method of clearing off
green fog. He recommends the following solution to be used after fixing:—
℞ Ferric chloride 50 grs.
Potassium bromide 30 grs.
Water iv ℥
The plate should be well washed after this treatment, and developed up
with the ferrous oxalate developer.
But such plates are not always saved artistically by the method, for the
tonality may be thrown out, and the texture of substances is nearly always
damaged.
[Sidenote: Frilling.]
Is due to the expansion of the gelatine, and will rarely occur if the
plate be put in the alum bath before fixing. The gelatine can be made to
contract by soaking in methylated spirits of wine.
[Sidenote: Blisters.]
Are of rare occurrence, and will dry out if the plate be carefully handled
and washed in alum, as directed. They may be treated locally with
methylated spirit, which causes the gelatine to contract.
[Sidenote: Dense negatives.]
The best reducer we know of is Dr. Eder’s. He recommends the use of—A.,
one part chloride of iron to eight parts of water. B., two parts neutral
oxalate of potash to eight parts of water. A well-known authority on
photographic matters, Dr. H. W. Vogel, says, “Both solutions keep a long
time without deteriorating. Immediately before using, equal parts of A.
and B. are mixed, forming a bright green solution, which keeps well for
several days in the dark, but decomposes in the light. Of this mixture a
little is added to a fresh and strong solution of ‘hypo.’ In difficult
cases 1 part ‘hypo’ and 1/4 to 1/2 of iron solution are employed. The
plate to be reduced is placed in this solution. The image weakens quickly
and uniformly. The plate is taken out and washed just before the desired
reduction is reached, because the action continues during the washing,
gradually diminishing under the stream from the tap. This reducer acts on
plates developed either with ‘pyro’ or ‘oxalate,’ and does not destroy the
details in the shadows like cyanide. There is also less tendency to frill
than with the cyanide bath.”
Reducers, like intensifiers, should not be resorted to, unless in case of
a very valuable negative, for it must never be forgotten that, though the
printing density is reduced, the tonality is not corrected.
[Sidenote: Yellow stains.]
Due to the developer, are easily removed by Edwards' clearing solution,
which we have found most effectual—
℞ Sulphate of iron ℥ iii.
Alum ℥ i.
Citric acid ℥ i.
Water O i.
[Sidenote: Transparent spots.]
Are due to dust in camera or slide, or to using the “hypo” bath too long.
If the spots have sharply defined edges, they are due to air bubbles
forming at the beginning of development.
[Sidenote: Halation.]
This is a bug-bear we have had little experience of, though we have taken
many interiors. The only occasion on which we met with it was once when
the plate was overexposed on a stained glass window, containing much blue
in it. If a large stop be used, and the exposure kept as short as
possible, our experience is that no halation need occur. If, however, the
student fears it, and there is always a danger of it where any bright
lights act on the film, he should, with a squegee and some glycerine,
apply a piece of some dark tissue to the back of the plate; this is easily
stripped off before development.
[Sidenote: Defects due to damp.]
All plates should be kept in a dry place, and whilst travelling it is as
well to keep them in tinfoil. The effect of damp is to produce patches,
which either do not develop at all or develop unequally.
[Sidenote: Removal of varnish.]
This is easily done by putting the plate into hot methylated spirit, and
rubbing the varnish off with cotton wool.
[Sidenote: Sea air.]
It has been said that sea air affects gelatine plates, this has not been
our experience.
[Sidenote: Dirty backs.]
The backs of the negatives which are generally dirty, should be cleaned by
scraping, and then rubbing up with a rag moistened in hot water, or
preferably, methylated spirit. The negatives should be kept in a dry
place, in grooved cardboard boxes. Wooden boxes should not be used for
storing either plates or negatives.
[Sidenote: Marblings.]
Are due to a dirty fixing bath; or to an uneven action of the developer
arising from not rocking the plate, or to adding the alkali to the
developer in the dish and not thoroughly mixing them before putting in the
plate. The clearing solution removes some of these.
[Sidenote: Prolonged and patchy fixing.]
Due to the alum bath being used before “fixing” in plates from which the
developer has not been thoroughly washed. It can be remedied by washing
and swilling the plate in water just rendered alkaline by ammonia, and
then fixing as before. We once had a plate which took several hours to fix
even after this treatment.
[Sidenote: Limpet-shell markings.]
We have had these appear in a few negatives some months after development.
We know of no remedy for the defect; nor do we know the cause, but believe
it to be due to hyposulphite of soda left in the film.
[Sidenote: Deposit on film.]
This is sometimes met with after the imperfect washing out of hyposulphite
of soda; or sometimes whilst the negative is in the fixing bath, if it has
been in the alum bath previously, and not thoroughly washed. Sulphur is
deposited. The remedy is obvious.
[Sidenote: Metallic patches.]
Coloured metallic-looking patches appear at times near the edges of the
plate, which may, or may not, be accompanied with fog. We have often
observed these patches in plates which have been kept a long time. There
is no remedy if they are unaccompanied by fog, but if fog is present, the
ferric-chloride solution will generally remove them.
[Sidenote: Scratches.]
On the back of the negative show as dark lines in the film.
[Sidenote: Undeveloped islands.]
Rarely, we have met with small patches which seem to have refused to
develop; they are generally circular. Captain Abney says they are due to
the use of chrome alum in the emulsion. There does not appear to be any
remedy for this accident.
[Sidenote: Dull spots and pits.]
In one batch of plates we were greatly troubled by these faults, one of
the plates being covered with pits as thickly as if it had been peppered
with a pepper-box. Captain Abney says they are due to the use of gelatine
which contains grease. They ruined a whole series of fine negatives for us
once. These complete the enumeration of the accidents likely to occur
during development.
[Sidenote: Varnishing.]
We shall now presume that the student has thoroughly dried his negatives,
after having developed them. Before storing them, however, he must varnish
them, to protect them from scratches, and especially from damp, for
gelatine, being very hygroscopic, easily absorbs moisture. At times, when
warming an apparently perfectly dry negative over a flame, preparatory to
varnishing it, a slight steam can be seen to arise, due to the evaporation
of the moisture in the film. This moisture in the gelatine would of course
in time lead to decomposition, and ruin the image; for these reasons,
then, all negatives should be varnished. Before “varnishing” each negative
should be carefully brushed over with a camel’s-hair brush. [Sidenote: Dr.
Carey Lea’s Varnish.] Now it is obvious that many of the varnishes used
are more or less non-actinic, as Dr. Carey Lea has proved; he, therefore,
recommends the following:—
℞ Bleached lac ʒ x.
Picked sandarac ʒ v.
Alcohol ℥ xii.
Let the lac dissolve in the alcohol, then filter, first soaking the filter
paper with alcohol. Pour slowly, and if necessary at the end add 1 ℥ more
of alcohol to enable the rest to pass. Next add the sandarac to the
filtrate and refilter, using of course a fresh filter.
Warm the plate gently, and, holding it in the left-hand bottom corner
between the thumb and finger, pour a pool of varnish on to the plate that
will cover about one-third the area of the plate, then let it run to the
right-hand top corner, then to the left-hand top corner, then to the
thumb, and finally drain off at the right-hand bottom corner into a
filter. Then place it on a drainage rack, till just set, when rewarm by
the fire, otherwise it does not set hard and smooth.
[Sidenote: Roller slide.]
Since paper negatives and a roller slide were suggested by Fox Talbot, and
made fit for use by Blanquart-Evrard, several ingenious persons have been
trying to improve upon these early attempts. From time to time, during the
last fifty years, various workers have announced old ideas as new
discoveries, nor have these been confined to roller slides and paper
negatives, but extended to many other photographic processes. That no one
can claim any originality of discovery on this head since Talbot and
Evrard is obvious; only perfected methods can be claimed. There have been
many of these introduced, but none worth discussing until that offered by
the Messrs. Walker and Eastman. They have perfected Talbot’s and Evrard’s
work, and though they have numerous imitators, their work is _facile
princeps_.
[Sidenote: Paper negatives.]
Now the student will naturally expect us to give an opinion on these paper
negatives. For many photographic processes they are of course invaluable,
but for artistic work our opinion is that they are not equal to the
ordinary method. These remarks apply equally to the various flexible films
which have lately been introduced.
For hand cameras, we should think, film negatives would be very useful,
and for small studies such as they produce, would do well; but then such
are not pictures. A picture must be perfect in all points, and for this
reason the films will not as yet answer. They do show grain, say what
people will; we have examined dozens of the very best, and that is our
opinion. Besides this, they are liable to the defects common to paper,
such as transparent spots, and the defects common to films, such as
markings and stains, and in addition to all this there is the liability to
injury of the negative after development, in the subsequent processes of
oiling and stripping, if stripping films be used. The quality, too, of the
picture is not equal to that of an ordinary negative. Why it is so we
cannot explain. What the future of these processes may be we do not
pretend to say, but for the present we feel assured that the finest
quality of work is to be obtained on a glass support. For ordinary touring
purposes no doubt the roller-slide and flexible films have every
advantage, but with any but the art side of the question we have nothing
to do. In artistic work, all hap-hazard results or accidental effects must
be carefully eliminated. Lightness, printing from either side, and a good
retouching basis are no considerations for the artist, he wants none of
these things.
[Sidenote: Ortho-chromatic photography.]
There still remains, however, a very important point from the art point of
view, as regards tonality, for as the student who has read his chemistry
knows, the different parts of the spectrum act differently on the
different haloids. The effect of this has been to destroy true tonality,
thus a yellow flower comes out black if taken on ordinary plates. To
remedy this dyes have been used which absorb the weakly acting rays, and
thus has been made one of the greatest advances in photography, both
scientifically and artistically. This ortho-chromatic photography has
engaged the attention of experts, and Abney, Vogel, Eder, Ives, Bothamley,
and Edwards are hard at work upon it now, besides many amateur scientists.
We have been for some time experimenting in this direction for artistic
purposes, having begun with Tailfer’s plates before any others were
introduced into the English market. For the photographing of pictures
Messrs. Dixon and Grey conclusively proved the superiority of the process
by their exhibits at the Exhibition of the Photographic Society of Great
Britain, in 1886. But the matter is different when landscapes and
portraits from life have to be considered. It is with the wonderful
protean aspects of nature that we have to deal when working from nature,
and we feel the question is not one to be entirely settled in the
laboratory. Our method is always to work out of doors, noting, as far as
possible, the conditions and judging the results by the prints, and though
such experiments are far from conclusive, we can at present say that the
ortho-chromatic plates are nearly correct in the rendering of tonality,
but not perfect, the reds overrun the other colours, and are too strongly
rendered. In fact, the reds and greens are not perfectly rendered, and
even if the correct values of the spectrum are rendered in a laboratory,
this will not and does not give the relative tones of nature. This is the
point which must be remedied. Undoubtedly ortho-chromatic photography
alone will be used in the near future, but just at present it is not
cut-and-dried enough for all practical purposes. The student, however,
must use these plates. They are supplied by B. J. Edwards; and Dr. Vogel’s
eoside of silver plates can be bought of Gotz, 19, Buckingham Street,
Strand. So far the truest tonality that we have seen has been obtained on
Dr. Vogel’s plates, and in addition his landscape plates require no yellow
screen to be used with them, which is a tremendous advantage.
[Sidenote: Final.]
Thus it will be seen that in every operation the art-knowledge of the
operator will tell. For example, let us suppose a camera set up with the
lens fixed, before a beautiful landscape composed on the ground-glass
screen by an artist, then let us imagine that two photographers proceed to
take plates of the picture. After the very first operation of focussing,
stopping and adjusting the swing-backs; a mighty gulf will separate the
two pictures; the gulf widens as the exposure is made, and finally in the
developed plates they are no longer the same thing. One may be a sharp,
common-place fact, false in many parts, the other may be full of truth and
poetry. Let a print be taken from each plate and presented to an
artistically uneducated craftsman and to an artist, the craftsman will go
into raptures over the sharp craftsman picture, the artist will do the
same over the artistic picture, but the artist will not look for a moment
at the craftsman’s ideal, and this little matter any one can prove for
himself. Let the student, then, strive to earn the artist’s praise, and
let him ignore the craftsman’s, and value his opinion on these matters at
the same price he would value his opinions upon any other subject where
taste and refinement are called into question.