This is still a secret with some in the profession. A limited number
of workers have succeeded in bringing out good opals, and their _modus
operandi_ is kept from the many. Now this is a pity, when one considers
the great charm attached to a good picture on opal, with pure whites and
rich blacks, and in many localities the demand that might be created for
them. Apart from their beauty, another charm attaches to opals--their
absolute permanence; and this, it must be allowed, is no trifle. What,
in fact, can be more painful to the worker who values his work, and sets
store by it, than to feel it must ere long fade and pass into oblivion!
A properly executed opal will no more fade than the glass pictures so
common at one time, and which, wherever taken care of, are as perfect
now as they were when first taken.
Now, excellent pictures are to be made on opals by means of emulsion;
but I propose first taking the transfer method (mainly applicable to
ground opal and canvas) as given above for pottery, since in practice
it is found very ready, easy of manipulation, and safe. The details are
much the same as above, and necessitate double transfer.
After the picture had been obtained on the plate (ordinary glass plate),
and after thoroughly fixing, washing, and toning, the picture (and this,
remember, is the case likewise with terra-cotta) then has to be loosened
from its support, and this is done with a solution of sulphuric
acid--one drachm to fifteen ounces of water--which is made to flow
between the image and the glass, after which perfectly wash and mount.
When the image is loosened a piece of tracing paper is put on the image,
evened out, raised (assisted by some one else to hold the two opposite
corners during the operation), and with the aid of the helper the
picture is carefully centered, gently pressed out or down, and the
transfer is so far effected. But what will happen, and does happen,
in the case of vignettes, is impurity of the whites, when the picture
becomes positively objectionable. Now the way to remedy this lies simply
in the application, to the dirty-looking parts, of a solution of iodine
dissolved in iodide of potassium to sherry color; after which, well wash
and apply a weak solution of cyanide of potassium, and wash well again.
This, by the way, is equally applicable to paper transfers; and it is
to be remembered that the toning comes last of all. It is a rather
difficult matter to clean a ground opal which has been used two or three
times, and acid must then be had recourse to (nitric acid is as good as
any); but by transferring from the support on the ground surface, all
stains are at once avoided.
On the flushed glass, or on the pot metal (unground), after well
cleaning the surface it should be covered with a substratum of egg. Then
the picture is taken direct, not transferred; that is, the plate is
exposed direct in the camera, regularly proceeded with, and, when dried,
varnished with a pale negative varnish, or with dead varnish if intended
for chalk or water-color. This, when a good negative is used, gives a
remarkably fine picture, not requiring a vestige of retouching, and
having likewise the invaluable advantage of being perfectly durable
if varnished with the negative varnish. Moreover, on that, effective
pictures may be made in oil with simply tinting.
A gentleman, who has a right to be considered a good judge in all art
matters, on looking at one of these pictures transferred on flushed
glass, said it was one of the finest productions of photography. He
urged that negatives _ad rem_ should be taken most carefully, and that,
like the picture I showed him, they should be full of half-tone and
detail, and yet have plenty of vigor. They should, he said, be robust in
the high lights, have perfectly clear glass in the few points of deep
shadows, and thus have powerful relief. Moreover, the negatives should
be retouched only by a competent hand, and care taken that the likeness
shall be in no way altered, which is so frequently the case now.
If done as thus suggested there is no doubt that remarkably fine
pictures are to be produced on opal, whether ground or not. Most
artistic results are to be obtained, and, with proper care, absolute
permanency. In this age of keen competition, all have to think of what
may be really recommended to one's _clientèle_, and likely to meet with
approbation from strangers and friends when the picture has once been
delivered; and I candidly think that the opal, of all, is the picture
most likely to meet with this general approbation.
I hope I have left it clearly to be understood that the class of opal
picture to which I have chiefly alluded is one that remains untouched
after the transfer--that is, absolutely unpainted upon. It is pure
photography in every sense of the word, and the resultant picture one
hardly to be surpassed in any way. I have rather laid a stress on this
point, well knowing how pictures are at times irretrievably ruined by
the barbarous hand of would-be artists, who by far exceed the true
artists in number; and the hint on retouching should not be lost sight
of, either, at a period when the tendency is to stereotype every one
in marble-like texture, or rather lack of texture, as if the face were
devoid of all fleshiness and as hard and rigid as cast-iron. It might
be wise to weigh this point carefully, and act upon it, before the
enlightened public have raised a cry against the pernicious practice
and made photographers smart for their want of applying timely remedial
measures to a decided evil.
On reading the above again, fearing lest any misconception should arise
in the mind of the reader, I deem it expedient, to clearly state that
for terra-cotta recourse is had to double transfer; that is, the picture
first taken is lifted from the support on tracing paper, put in
the right position on terra-cotta, and pressed down while wet with
blotting-paper, left to dry, and is then so far ready.
Respecting the production of pictures by means of emulsion, ground opal
being the best, the system I employ is as follows: After well cleaning
the glass, coat it with emulsion (which had better not be too thick).
When dry it is exposed and developed with the usual oxalate developer,
to which a little bromide of potassium has been added. The remainder of
the operations is as usual. Those varnished with dead varnish can be
tinted and worked up with colored crayons or black lead pencil and make
very pleasing pictures. It is needless to add that they are also to be
finished in water-colors if thought preferable.--_G. W. Martyn, in Br.
Jour. Photo_.
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