The photographic news

• Bandzählung: 13.1869
• Erscheinungsdatum: 1869
• Sprache: Englisch
• Signatur: F 135
• Vorlage: Hochschule für Grafik und Buchkunst Leipzig
• Digitalisat: Hochschule für Grafik und Buchkunst Leipzig
• Digitalisat: SLUB Dresden
• Rechtehinweis: Public Domain Mark 1.0
• URN: urn:nbn:de:bsz:14-db-id1780948042-186900000
• PURL: http://digital.slub-dresden.de/id1780948042-18690000
• OAI: oai:de:slub-dresden:db:id-1780948042-18690000
• Sammlungen: LDP: Historische Bestände der Hochschule für Grafik und Buchkunst Leipzig
• Sammlungen: Fotografie
• Bemerkung: Heft 545 (S. 73-84), Heft 547 (S. 97-108), Heft 589 (S. 599-610) fehlen in der Vorlage. Paginierfehler: Auf Seite 444 folgt Seite 443
• Strukturtyp: Band

• Digitalisat: SLUB Dresden
• Strukturtyp: Ausgabe

266 THE PHOTOGRAPHIC NEWS. [Junk 4, 1869. are prepared at one time, and generally two hands are at ■work on them at the same time, tl e one to wash, the other to coat with albumen. “ When wanted for use they are taken out of the pack ages, and one after the other wetted all over under a flowing tap. A saturated solution of sulphate of iron acidified with sulphuric acid is now poured over the plates, the same as if you were developing the plate ; the solution is mad > t flow over the plate in one continuous, unbroken wave, and kept floating upon the plate for a short time, and afterwards washed in abundance of water. It is now placed in the rack before a brisk fire, and dried. After they are dried, they are carefully cleaned upon the back and marked, as it would now be difficult to find out the prepared surface. I have never experienced any difficulty in covering the plate with collodion. “ In preparing the albumen, I take white of eggs with the germs carefully taken out, and beat them up in a bason for some fifteen to twenty minutes till it gets into light, white froth. It is allowed to settle, and three parts of water to one of egg are added, and filtered into a large bottle : liquor of ammonia is added till it sensibly smells of it. This helps to preserve it. “ The advantages of a preliminary coating of albumen to the glass are cheapness in the price of flattened sheet for large plates ; the collodion, however tender, adheres with tenacity, and is with difficulty removed; less labour, and more certainty in the preparation of the plates ; freedom from blemishes of every sort; the negatives will stand much rougher usage, and are somewhat firmer in texture; and I do not find the bath more liable to get out of order than with plates in common use. I have worked with baths until they were unfit for use from the large quantity of etlier and alcohol they contained, without having a foggy plate. I have thought that after long use they showed symptoms of loss ot sensitiveness, but I am not quite sure, but that the same may be said of a bath somewhat improved from constant use, when it begins to show symptoms of coming age. “ To all who are in the habit of using large plates for out-door work or copying, or printing large transparencies, it offers many advantages, not the least being a temper un ruffled by losing films from off the plates, and perfect immunity from spots and blemishes, so far as the prepara tion of the. plates is concerned.” It will be seen that Mr. McNab’s arrangements compre hend facilities for using this method on a large scale, and that he finds many advantages, and no defects, in using it for wet plates. His albumen solution is not very dilute, but recent experience has shown that the strength may be reduced very considerably without disadvantage. Mr. Fry uses one part of albumen in ten of water; another trust worthy correspondent, signing “ Kent,” says he has found it answer when diluted to one part in thirty of water. It is probable that when used thus dilute its physical advantages in securing adhesion and cleanliness will be more marked than the chemical action in securing vigour and richness of colour, at one time sought successfully by its use. For one especial purpose the albumen coating possesses an important advantage : we refer to its use upon old plates. An experienced portraitist recently remarked to us that a stock of dilute albumen was always kept ready in his establishment, and applied as an invariable rule to all plates which had been once used, giving an absolute immunity from the trouble of dirty plates. It was also generally used for large plates required for the Sarony photo-crayons, and prevented many risks whilst giving a rich image. We think the evidence in favour of albumen preliminary coatings, under proper conditions, is tolerably conclusive, even in the wet process, and we feel satisfied that by a careful observation of conditions, general success might be obtained with its use in dry-plate work, even in those cases in which hitherto its tendency to blister has been an insuperable objection. SINGULAR CAUSE OF SPOTS IN PRINTS. A curious cause for the minute yellow spots which frequently trouble portraitists was recently traced to its source by one of our correspondents. It is scarcely probable that the. same cause is in frequent operation, but a brief account of the matter may be interesting and suggestive. In the case to which we refer the spots had perplexed our correspondent for many months past. They were minute and numerous, yellow in colour, with a dark centre. The most obvious cause for the spots appeared to be imperfect fixation. When our advice was sought on the subject, it seemed certain to us that imperfect fixation was the immediate cause, and that the spots were due to the formation of minute bubbles on the surface of the print when it was immersed in the hypo fixing bath. Attention to this and all other ordin ary causes of spots did not, however, serve to get rid of the evil. Sample after sample of paper, sample after sample of silver, gold, and hypo was tried in succession, but without any mitigation of the trouble, and as a large portion of the work done consisted of card vignettes, the spots were as obtrusively apparent as they were disastrous. The printer was a careful and trustworthy man ; but all his care failed to discover either the cause or means of avoiding the spots. At length the cause was discovered in a very unexpected quarter; the principal of the establishment went into the printing room one morning early, to see if the spots were as plentiful and troublesome as ever. He noticed that many of the prints had floated to the top of the water in the large washing trough, the surface of the water being covered with a dusty deposit. On examining carefully he found that wherever this dust rested on a print, a spot was found under each particle; and on further examination he found that the dust partook of the nature of very fine ashes. Gradually he traced the whole facts : a stove in which coke was burnt as fuel was used to warm the room, and the coke in use at the time had contained a large proportion of sulphur, the especial visitation of the spots being consequent on the purchase of a new stock of coke, which turned out to be of inferior quality. With the disuse of the fire the spots at once disappeared, and have not been seen since. “REMBRANDT EFFECTS,” AND HOW TO PRODUCE THEM. We have received recently from America some examples of what are termed “ Rembrandt Effects,” which are exciting interest amongst our transatlantic cousins at present. The effects in question are produced by applying to portraiture a similar system of lighting to that occasionally employed with statuary, of which the well-known photograph of a figure entitled “ Purity ” was one of the earliest and most popular examples. In some of the examples we have seen the result is very striking and effective. The figure is generally vignetted into a very dark background : the face, which is generally in profile, is generally in a dark mezzo tint throughout, except the outline of the features, which is illuminated with a brilliant line of light, which may also just tip other portions of the outline. Sometimes a full face or three-quarter view may be taken, but the same principle is retained: the features generally being kept in half-shadow, some portions only being brilliantly lighted. In these pictures the mass of the subject throughout is kept in shadow, to give intense value to the minute portions of brilliant light, chiefly on the head; the general balance of light and shade suggesting the title which has been given to the style in the States, “ Rembrandt Effects.” Amongst the most successful of the producers of this class of picture the works of Mr. Kurtz, one of the most able of the New York portraitists, and Mr. W. J. Baker, have excited most attention. The latter gentleman, writing in the Phila delphia Photographer on the subject, describes his mode of producing them. Wo subjoin a condensation of his emarks.