Suche löschen...
The photographic news
- Bandzählung
- 7.1863
- Erscheinungsdatum
- 1863
- Sprache
- Englisch
- Signatur
- F 135
- Vorlage
- Hochschule für Grafik und Buchkunst Leipzig
- Digitalisat
- Hochschule für Grafik und Buchkunst Leipzig
- Digitalisat
- SLUB Dresden
- Lizenz-/Rechtehinweis
- Public Domain Mark 1.0
- URN
- urn:nbn:de:bsz:14-db-id1780948042-186300004
- PURL
- http://digital.slub-dresden.de/id1780948042-18630000
- OAI-Identifier
- oai:de:slub-dresden:db:id-1780948042-18630000
- Sammlungen
- Fotografie
- LDP: Historische Bestände der Hochschule für Grafik und Buchkunst Leipzig
- Strukturtyp
- Band
- Parlamentsperiode
- -
- Wahlperiode
- -
- Bandzählung
- No. 227, January 9, 1863
- Digitalisat
- SLUB Dresden
- Strukturtyp
- Ausgabe
- Parlamentsperiode
- -
- Wahlperiode
- -
-
Zeitschrift
The photographic news
-
Band
Band 7.1863
-
- Titelblatt Titelblatt -
- Ausgabe Ausgabe 1
- Ausgabe Ausgabe 13
- Ausgabe Ausgabe 25
- Ausgabe Ausgabe 37
- Ausgabe Ausgabe 49
- Ausgabe Ausgabe 61
- Ausgabe Ausgabe 73
- Ausgabe Ausgabe 85
- Ausgabe Ausgabe 97
- Ausgabe Ausgabe 109
- Ausgabe Ausgabe 121
- Ausgabe Ausgabe 133
- Ausgabe Ausgabe 145
- Ausgabe Ausgabe 157
- Ausgabe Ausgabe 169
- Ausgabe Ausgabe 181
- Ausgabe Ausgabe 193
- Ausgabe Ausgabe 205
- Ausgabe Ausgabe 217
- Ausgabe Ausgabe 229
- Ausgabe Ausgabe 241
- Ausgabe Ausgabe 253
- Ausgabe Ausgabe 265
- Ausgabe Ausgabe 277
- Ausgabe Ausgabe 289
- Ausgabe Ausgabe 301
- Ausgabe Ausgabe 313
- Ausgabe Ausgabe 325
- Ausgabe Ausgabe 337
- Ausgabe Ausgabe 349
- Ausgabe Ausgabe 361
- Ausgabe Ausgabe 373
- Ausgabe Ausgabe 385
- Ausgabe Ausgabe 397
- Ausgabe Ausgabe 409
- Ausgabe Ausgabe 421
- Ausgabe Ausgabe 433
- Ausgabe Ausgabe 445
- Ausgabe Ausgabe 457
- Ausgabe Ausgabe 469
- Ausgabe Ausgabe 481
- Ausgabe Ausgabe 493
- Ausgabe Ausgabe 505
- Ausgabe Ausgabe 517
- Ausgabe Ausgabe 529
- Ausgabe Ausgabe 541
- Ausgabe Ausgabe 553
- Ausgabe Ausgabe 565
- Ausgabe Ausgabe 577
- Ausgabe Ausgabe 589
- Ausgabe Ausgabe 601
- Ausgabe Ausgabe 613
- Register Index 619
-
Band
Band 7.1863
-
- Titel
- The photographic news
- Autor
- Links
- Downloads
- Einzelseite als Bild herunterladen (JPG)
-
Volltext Seite (XML)
THE PHOTOGRAPHIC NEWS. Vol. VII. No. 227.—January 9, 1863. aC- re- ch ins of er- to ib- bt- I., but ! en | 214 A 164 : as I to ne- ent use the ttle the nd rise and n it ver \ny ■ by im- wn. i ing I Iver g to een has tise- the . bad. can : such i nan, : teet- 5 the end. 1 ' the you the ults. ? back j lull find used I The is is | ‘apid rhich ■ not orth par pro- e. If itive. • con* some- entl r the icitel ) co# cialll Iway, ense ’ thef We egi. ert aeav IS fo srg PHOTOZINCOGRAPHY* The work of Col. James and Captain Scott, on photo zincography, is one of the most interesting books which have been published in connection with the art, not simply as a complete and detailed statement of the processes and formulas used at Southampton, but for the variety of fine reproductions in printer’s ink with which it is illus trated. Referring to the latter first, we arc enabled to endorse the opening remark in Col. James’s introduction, as to the high state of perfection to which these processes have been brought at Southampton. For reproduction of engravings and similar subjects, wc have before said, that both the process of Col. James and that of Mr. Osborne have reached a pitch of excellence which leaves little to attain or desire. Amongst the dozen photographic illustrations given in this book are exquisite copies of engravings, some of which have a great deal of fine, close work, which is most perfectly rendered. We may mention amongst these a reduced copy of a fine engraving from a painting by Raffaello ; two of Piranesi’s engravings of antique vases of rare design; and a reduced copy of one of Volpato’s engravings of a panel in the Vatican, painted by Raffaelle. There are also fine specimens of hill shading, and fine detail in maps ; a reduced copy of an indenture ; a page of Domesday Book ; and a page of the folio edition of Shakespeare of 1623. Each of these are perfect illustrations of the value of the art for the several kinds of work represented. The technical details of the work will be read with much interest and attention amongst photographers. The pro cesses are divided for clearness into three parts. These consist in the production of the negative ; the preparation of the positive photographic print in greasy ink; and the transference of the print to the surface of the zinc, or to stone, and the preparation of that surface for printing. These processes are here more fully described than in any previous work, and a brief resum6 will doubtless be interesting to our readers. It must always be borne in mind, that the negative most suitable for giving good results on the lithographic stone, is one perfectly dense in the whites of the picture, and quite clear and transparent in the blacks; in short, great bril liancy, intensity, and freedom from any trace of foggy deposit on the shadows, and as in engravings, maps, &c., the gradation is secured by the artificial means of lines, hatching, or stippling, the gradation known by photogra phers as half tone, is not required in the pictures. The collodion used is simply iodized, and is preferred about a fortnight old. The formula given stands as fol lows :— Pyroxyline 80 grains Iodide of cadmium 15 „ Iodide of potassium 75 „ Alcohol sp. gr. 812 10 ounces Ether sp, gr. 725 10 „ 1 ho usual silver bath of from 35 to 40 grains to the ounce of water is used, slightly acid with nitric acid, in preference to acetic acid. * On Photozincography and other photographic processes employed at the Ordnance Survey Office, Southampton. By Captain A. De C. Scott, R.E., under the direction of Col. sir Henry James, U.K., F.H.S, Ac. London : Longman A Co. The development is effected by iron. The formula stands thus :— Protosulphate of Iron 1 ounce Glacial Acetic Acid 6 drachms Alcohol 6 „ Distilled Water 1 pint. The image is sufficiently developed by means of this solu tion, especial care being taken to stop its action before there is the slightest trace of deposit on the fine lines or shadows. Further intensity is then secured by the application, after fixing, of pyrogallic acid, a grain and a half to the ounce, twenty-four minims of acetic acid, and a few drops of a solution of silver. If further intensity be required the nega tive is immersed in a weak solution of bichloride of mercury until its surface is whitened; it is then treated with a weak solution of hydrosulphate of ammonia, which gives the required density. To prevent lateral deposit filling up the fine lines, the last process of intensifying is effegted after the plate has been suffered to dry, the edges being varnished to prevent the film slipping. The apparatus used for convenient copying was fully described in the Photographic News, Vol. III., and we do not find that any material alteration has been made except in the adoption of Dallmeyer’s triple achromatic lens for copying. To produce the transfer the paper must be hard, thin, and tough, of even texture, and free from woolliness, and but slightly sized. Paper made from linen is most suitable; the best results have been obtained with the ordinary bank post paper, slightly sized. The proportions of the bichro mate and gelatine—gum has long been abandoned—vary with circumstances. It is necessary that the solution of gelatine be fluid at a temperature of 100°, and that the proportion of bichromate be sufficient to render the whole ofnthe gelatine insoluble under the action of light, but no more. The quantities here stated are two ounces and a half of bichromate of potash dissolved in ten ounces of hot water, added to three ounces of gelatine, dissolved in forty ounces of hot water. The fluidity is maintained by placing the dish containing the mixture in another containing hot water. The paper is floated for a few minutes, and when dried, the process is repeated, When again dry it is passed through a copper-plate press, on a hot steel plate. The time of exposure to the negative varies, from one minute in the sun, to twenty minutes in dull light. When sufficiently exposed, the blacks appear of a brownish green. The transfer ink, is made as follows :—two pounds of chalk lithographic ink, and one pound of middle linseed oil varnish are ground together; four ounces of Burgundy pitch are melted in an iron vessel, and to it are added two ounces of palm oil, and two ounces of white wax; these are well stirred together on the fire until they begin to burn. The ink and varnish, first mixed, are then added, and the whole thoroughly incorporated. For use, a portion of this is thinned with turpentine to the consistency of thick, treacle. To apply this ink to the | surface of the print, a zinc plate or lithographic stone is inked in the usual method with aroller ; the bichromate print is then laid face down, and passed through a lithographic press. By this means the whole of the surface is covered with a uniform surface of ink. To remove the ink from every part but the image, the print is floated for five minutes on water at 90° Fah. back
- Aktuelle Seite (TXT)
- METS Datei (XML)
- IIIF Manifest (JSON)