Suche löschen...
The photographic news
- Bandzählung
- 12.1868
- Erscheinungsdatum
- 1868
- 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-id1780948042-186800009
- PURL
- http://digital.slub-dresden.de/id1780948042-18680000
- OAI-Identifier
- oai:de:slub-dresden:db:id-1780948042-18680000
- Sammlungen
- Fotografie
- LDP: Historische Bestände der Hochschule für Grafik und Buchkunst Leipzig
- Strukturtyp
- Band
- Parlamentsperiode
- -
- Wahlperiode
- -
- Bandzählung
- No. 510, June 12, 1868
- Digitalisat
- SLUB Dresden
- Strukturtyp
- Ausgabe
- Parlamentsperiode
- -
- Wahlperiode
- -
-
Zeitschrift
The photographic news
-
Band
Band 12.1868
-
- Titelblatt Titelblatt I
- Kapitel Preface III
- 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 The Index To Volume XII 619
-
Band
Band 12.1868
-
- Titel
- The photographic news
- Autor
- Links
- Downloads
- Einzelseite als Bild herunterladen (JPG)
-
Volltext Seite (XML)
June 12, 1868.] THE PHOTOGRAPHIC NEWS. 285 according to the greater proportion of colouring in the gela tine.’ He had obtained good effects by washing the sensitive paper before printing. That washing (five minutes at most) was for the purpose of getting rid of an excess of bichromate of potash, which made the paper yellow, and was an obstacle in the way of rapid printing. By proceeding in this manner ho obtained proofs of great delicacy. M. Vidal thought that the preliminary washing would be useful with rather thick paper, but he considered it not only useless, but injurious, when applied to tissues. Ho had tried it, and found that, in the latter case, the sensitiveness was almost completely destroyed ; but ho believed that in the case of thick paper there remained, in spite of the washing, sufficient bichromate of potash to maintain the sensitiveness of the layer io be impressed. The Chairman said that on a sheet of paper of which one- half only had been washed and the other not, he had observed that the part unwashed exhibited a granular image, while the washed half was free from that imperfection. M. Vidal showed some photometric bands obtained in the Vogel photometer. He considered the different degrees of in tensity were not sufficiently marked, and that his own plan, which consisted of a series of ten tints only, f om white to black, would be preferable. He also showed some fine specimens obtained by the helio-engraving processes of MM. Placet and Baldus ; of litho-photography by M. Lemercier ; enamel photo graphy by M. Lafon de Camarsac ; proofs, carbon (in different tones), by Braun, of Dornach ; and coloured photographs by M. Niepce de St. Victor. The engravings of M. Placet were considered the finest of the kind that had been submitted. The very remarkable proofs by M. Baldus were previously un known. His fine copies of the engravings of Marc Antony were particularly admired. The litho-photographic proofs sent by M. Lemercier, though very fine, did not exhibit any new practical progress in that art, as they were old specimens. With regard to the splendid enamels of M. Lafon de Camarsac, though they were well known, they were not the less admired. The magnificent reproductions of drawings of the great masters, by M. Braun, of Dornach, above all claimed the attention of the Society. His work is already monumental, as the number of drawings reproduced amounts to 3,354. Amongst them are the rod lead, sepia, and the grey tones of old china ink, by which the colours of the originals are admirably rendered ; and now that we can affirm that all the fine drawings of Raphael, Albert Durer, Leonardo da Vinci, Greuze, &c., are reproduced by the carbon process of photography in a manner that is in delible, it is impossible not to be enraptured with such a result, and not to pay to M. Braun a just tribute of eulogy and admira tion. These are the works which elevate the art of photo graphy, and prove that no art ever possessed a more sincere and more powerful auxiliary. The heliochromatic proofs of M. Niepce de St. Victor, whose first efforts in this direction had already been communicated to the Society, showed fresh progress. Some votes of thanks terminated the proceedings. orrespondence. PRACTICAL EXPERIENCE WITH SOME DRY PLATE PROCESSES. Sir,—Believing that landscape photographers in general feel the same interest that I take myself in the perfecting of the dry plate process, and having derived from almost every experience narrated in the News some benefit, I desire to return obligation, if possible, and throw the ray of my taper on the subject, still so much in the dark, of the preparation of that unattained desideratum, a perfect dry plate. I have experimented for nearly four years on all the dry processes I have heard of, except the coffee, which I judge to be substantially the same as the tannin, the extract of coffee producing in action on metals very nearly the same effect as tannic acid. I have made it a rule to stick to a process until 1 had mastered all the causes of failure, and produced practically normal results from it, and in so doing have many times exhausted a patience not easily tried. I believe, therefore, that the result of my hundreds of experiments—indeed, I think I might safely say thousands—may be of use, at least in saving time and patience to some who, like myself, have had to work out their system alone, and far from any prac tical assistance. I take it that the ideal dry plate must be possessed of the following qualities: —Firstly, it must develop so evenly that an open blue sky will be rendered without a vestige of clouding or unevenness. Secondly, that it should keep at least three months without deterioration or getting un certain. Thirdly, that they should be equal in sensibility. And, fourthly, that it should develop quickly, and without any tendency to fog. Extreme sensitiveness does not seem to me of great importance, and if a plate will take an im pression in less than ten minutes, with a tolerably certain result, I should be satisfied with it on that score. For the first qualification, I have found the collodio- albumen approach nearest perfection ; next to it, Gordon’s albumen process; and then the old-fashioned Fothergill. For the second, I have found nothing equal the much- abused tannin. My experimental plates, prepared with bromized collodion, and by Sayce’s process, have so invari ably fogged or peeled, that I have not gone far in that direction. For the third, I find the tannin and Gordon’s about equally reliable; and for the fourth, Gordon’s and (except under alkaline development) the tannin ; but, as everybody knows, all the albumen processes are free from fog, except with bromized collodion, or when the alkaline development is applied. The Gordon (albumen) process, on the whole, has given me the most satisfactory results, and, with tannin for certain emergencies presently to be spoken of, will, I believe, satisfy general demands better than any others of which I have thorough knowledge. Nor am I willing to accept the com monly received estimate of either of those processes. I have found the Gordon plates keep longer and resist high tempe rature better than they are represented to, having obtained spotless and clear transparencies from plates that I have had in my dark room three months ; and only a week ago, having some plates that I had prepared over two weeks before and brought back unused from an excursion at that time (since which time they were left in the slides), I took them with me on another, when I was using wet collodion, and ex posed them in a difficult ravine, where I could not get my dark box even, and with one of the hottest days of the sea son (90°, judging from sensation, and for many days about 80° in average exposure), I exposed my four plates, and got four negatives, of one of which I send a proof. Net a spot or mark of decomposition was to be seen on either of them. The only difference between my manner of preparing the plates and that prescribed in the Year-Book is, that after- taking the plate out of the distilled water, I flow over it a very weak aqueous solution of iodine,just enough alcoholic solution being dropped into the water to give it the colour of golden sherry, pouring it over and throwing it off twice ; and this I do for all processes which require entire ridding of the free nitrate. After the iodine, I wash with a jet of some little force, lest the particles of iodide should adhere. The weaker the iodine solution the better, so long as it converts the whole of the nitrate in the film, which will be shown to be accomplished by the solution retaining its colour. I de velop with strong pyrogallic acid solution, 4 or even 6 grains to the dunce, but never alkaline unless the picture refuses to come out for pyrogallic, even of the strength of 8 or 10 grains per ounce, and then only add to the developer half a grain of carbonate in preference to liquid ammonia. It is so much easier to restrain than force development, and there is so much less tendency to stain with full exposure, that the waiting of two or three minutes more or less seems of no account. There are few cases in which exposure ranging from four to eight times thatof wet collodionmay not be perfectly met by the development without losing the value of the highest light. I begin with a solution of pyrogal lic of the strength of about 2 grains, and if the picture
- Aktuelle Seite (TXT)
- METS Datei (XML)
- IIIF Manifest (JSON)