The History and Practice of the Art of Photography [46]
a red brick left. This brick was brought out on the Daguerreotype plate of precisely the same color as the brick itself. The same artist also exhibited to me, the full length portrait of a gentleman who were a pair of pantaloons having a blue striped figure. This blue stripe was fully brought out, of the same color, in the picture.--AMER. ED.
"In 1840 I communicated to Sir John Herschel some very curious results obtained by the use of colored media, which he did me the honor of publishing in one of his memoirs on the subject from which I again copy it."
"A paper prepared with muriate of barytes and nitrate of silver, allowed to darken whilst wet in the sunshine to a chocolate color, was placed under a frame containing a red, a yellow, a green, and a blue glass. After a week's exposure to diffused light, it became red under the red glass, a dirty yellow under the yellow glass, a dark green under the green, and a light olive under the blue.
"The above paper washed with a solution of salt of iodine, is very sensitive to light, and gives a beautiful picture. A picture thus taken was placed beneath the above glasses, and another beneath four flat bottles containing colored fluids. In a few days, under the red glass and fluid, the picture became a dark blue, under the yellow a light blue, under the green it remained unchanged, whilst under the blue it became a rose red, which in about three weeks changed into green. Many other experiments of a similar nature have been tried since that time with like results.
"In the summer of 1843, when engaged in some experiments on papers prepared according to the principles of Mr. Talbot's calotype, I had placed in a camera obscura a paper prepared with the bromide of silver and gallic acid. The camera embraced a picture of a clear blue sky, stucco-fronted houses, and a green field. The paper was unavoidably exposed for a longer period than was intended--about fifteen minutes,--a very beautiful picture was impressed, which, when held between the eye and the light, exhibited a curious order of colors. The sky was of a crimson hue, the houses of a slaty blue, and the green fields of a brick red tint. Surely these results appear to encourage the hope, that we may eventually arrive at a process by which external nature may be made to impress its images on prepared surfaces, in all the beauty of their native coloration."
PHOTOGRAPHIC DEVIATIONS.
Before taking leave of the subject of photogenic drawing, I must mention one or two facts, which may be of essential service to operators.
It has been observed by Daguerre, and others, in Europe, and probably by some of our own artists, that the sun two hours after it has passed the meridian, is much less effective in the photographic process, than it is two hours previous to its having reached that point. This may depend upon an absorptive power of the air, which may reasonably be supposed to be more charged with vapor two hours before noon. The fuse of the hygrometer may possibly establish the truth or falsity of this supposition. The fact, however, of a better result being produced before noon being established, persons wishing their portraits taken, will see the advantage of obtaining an early sitting, if they wish good pictures. On the other hand, if the supposition above mentioned prove true, a too early sitting must be avoided.
If we take a considerable thickness of a dense purple fluid, as, for instance, a solution of the ammonia-sulphate of copper, we shall find that the quantity of light is considerably diminished, at least four-fifths of the luminous rays being absorbed, while the chemical rays permeate it with the greatest facility, and sensitive preparations are affected by its influence, notwithstanding the deficiency of light, nearly as powerfully as if exposed to the undecomposed sunbeams.
It was first imagined that "under the brilliant sun and clear skies of the south, photographic pictures would be produced with much greater quickness than they could be in the atmosphere of Paris. It is found, however, that
"In 1840 I communicated to Sir John Herschel some very curious results obtained by the use of colored media, which he did me the honor of publishing in one of his memoirs on the subject from which I again copy it."
"A paper prepared with muriate of barytes and nitrate of silver, allowed to darken whilst wet in the sunshine to a chocolate color, was placed under a frame containing a red, a yellow, a green, and a blue glass. After a week's exposure to diffused light, it became red under the red glass, a dirty yellow under the yellow glass, a dark green under the green, and a light olive under the blue.
"The above paper washed with a solution of salt of iodine, is very sensitive to light, and gives a beautiful picture. A picture thus taken was placed beneath the above glasses, and another beneath four flat bottles containing colored fluids. In a few days, under the red glass and fluid, the picture became a dark blue, under the yellow a light blue, under the green it remained unchanged, whilst under the blue it became a rose red, which in about three weeks changed into green. Many other experiments of a similar nature have been tried since that time with like results.
"In the summer of 1843, when engaged in some experiments on papers prepared according to the principles of Mr. Talbot's calotype, I had placed in a camera obscura a paper prepared with the bromide of silver and gallic acid. The camera embraced a picture of a clear blue sky, stucco-fronted houses, and a green field. The paper was unavoidably exposed for a longer period than was intended--about fifteen minutes,--a very beautiful picture was impressed, which, when held between the eye and the light, exhibited a curious order of colors. The sky was of a crimson hue, the houses of a slaty blue, and the green fields of a brick red tint. Surely these results appear to encourage the hope, that we may eventually arrive at a process by which external nature may be made to impress its images on prepared surfaces, in all the beauty of their native coloration."
PHOTOGRAPHIC DEVIATIONS.
Before taking leave of the subject of photogenic drawing, I must mention one or two facts, which may be of essential service to operators.
It has been observed by Daguerre, and others, in Europe, and probably by some of our own artists, that the sun two hours after it has passed the meridian, is much less effective in the photographic process, than it is two hours previous to its having reached that point. This may depend upon an absorptive power of the air, which may reasonably be supposed to be more charged with vapor two hours before noon. The fuse of the hygrometer may possibly establish the truth or falsity of this supposition. The fact, however, of a better result being produced before noon being established, persons wishing their portraits taken, will see the advantage of obtaining an early sitting, if they wish good pictures. On the other hand, if the supposition above mentioned prove true, a too early sitting must be avoided.
If we take a considerable thickness of a dense purple fluid, as, for instance, a solution of the ammonia-sulphate of copper, we shall find that the quantity of light is considerably diminished, at least four-fifths of the luminous rays being absorbed, while the chemical rays permeate it with the greatest facility, and sensitive preparations are affected by its influence, notwithstanding the deficiency of light, nearly as powerfully as if exposed to the undecomposed sunbeams.
It was first imagined that "under the brilliant sun and clear skies of the south, photographic pictures would be produced with much greater quickness than they could be in the atmosphere of Paris. It is found, however, that