Suche löschen...
The photographic news
- Bandzählung
- 27.1883
- Erscheinungsdatum
- 1883
- 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-id1780948042-188300004
- PURL
- http://digital.slub-dresden.de/id1780948042-18830000
- OAI-Identifier
- oai:de:slub-dresden:db:id-1780948042-18830000
- Sammlungen
- Fotografie
- LDP: Historische Bestände der Hochschule für Grafik und Buchkunst Leipzig
- Strukturtyp
- Band
- Parlamentsperiode
- -
- Wahlperiode
- -
- Bandzählung
- No. 1280, March 16, 1883
- Digitalisat
- SLUB Dresden
- Strukturtyp
- Ausgabe
- Parlamentsperiode
- -
- Wahlperiode
- -
-
Zeitschrift
The photographic news
-
Band
Band
-
- Titelblatt Titelblatt I
- Register Index III
- Ausgabe Ausgabe 1
- Ausgabe Ausgabe 17
- Ausgabe Ausgabe 33
- Ausgabe Ausgabe 49
- Ausgabe Ausgabe 65
- Ausgabe Ausgabe 81
- Ausgabe Ausgabe 97
- Ausgabe Ausgabe 113
- Ausgabe Ausgabe 129
- Ausgabe Ausgabe 145
- Ausgabe Ausgabe 161
- Ausgabe Ausgabe 177
- Ausgabe Ausgabe 193
- Ausgabe Ausgabe 209
- Ausgabe Ausgabe 225
- Ausgabe Ausgabe 241
- Ausgabe Ausgabe 257
- Ausgabe Ausgabe 273
- Ausgabe Ausgabe 289
- Ausgabe Ausgabe 305
- Ausgabe Ausgabe 321
- Ausgabe Ausgabe 337
- Ausgabe Ausgabe 353
- Ausgabe Ausgabe 369
- Ausgabe Ausgabe 385
- Ausgabe Ausgabe 401
- Ausgabe Ausgabe 417
- Ausgabe Ausgabe 433
- Ausgabe Ausgabe 449
- Ausgabe Ausgabe 465
- Ausgabe Ausgabe 481
- Ausgabe Ausgabe 497
- Ausgabe Ausgabe 513
- Ausgabe Ausgabe 529
- Ausgabe Ausgabe 545
- Ausgabe Ausgabe 561
- Ausgabe Ausgabe 577
- Ausgabe Ausgabe 593
- Ausgabe Ausgabe 609
- Ausgabe Ausgabe 625
- Ausgabe Ausgabe 641
- Ausgabe Ausgabe 657
- Ausgabe Ausgabe 673
- Ausgabe Ausgabe 689
- Ausgabe Ausgabe 705
- Ausgabe Ausgabe 721
- Ausgabe Ausgabe 737
- Ausgabe Ausgabe 753
- Ausgabe Ausgabe 769
- Ausgabe Ausgabe 785
- Ausgabe Ausgabe 801
- Ausgabe Ausgabe 817
-
Band
Band
-
- Titel
- The photographic news
- Autor
- Links
- Downloads
- Einzelseite als Bild herunterladen (JPG)
-
Volltext Seite (XML)
of a great many plates in producing a very few worth showing ; while one of the third class has arisen out of the second, and it is on this subject I now address you. My many failures were occasioned by the extreme sensitive ness of the plates which I used, and this led me to consider whether it would not be possible to prepare plates which might be printed in the same manner as ordinary sensitized paper, in which the progress of the printing might be watched, and which would require no development. While cogitating on this sub ject, I came across Captain Abney’s description of an emulsion which seemed to suit all my requirements. It is an emulsion of gelatine, citrate of silver, and silver chloride, made with sodium chloride, 40 grains ; potassium citrate, 40 grains ; silver nitrate, 150 grains; gelatine, 190 ; water, altogether about 6 ounces ; and alcohol, 3 drams. I resolved to try a few specimens of these 'plates, but by accident I fortunately or unfortunately added a considerably larger quantity of the sodium chloride than was necessary. The result of this was that the silver, having more affinity for the chloride than for the citrate, was entirely taken up by the chlo ride, thus leaving the citrate free to be washed out with the un combined chloride and other soluble sa[ts. I also added, when re-melting, two drams of liquor ammonia, and boiled the whole for an hour at least. Practically my plates may be called gela tine chloride plates. When the plates were dry I tried one. It printed slowly and beautifully of a fine purple colour. When printed up to about the colour I Wanted it, when finished I put it into hypo, when the whole image vanished, and the plate appeared perfectly slean. I tried another, printed it until all detail was lost in the shadows, half tones gone, and even the high lights discoloured, fixed in hypo, with almost the same result. Still there was some colour in the film this time, but so little that this was also set aside as a failure. A third plate I tried, printed deep, soaked in a borax and chloride of gold toning bath, and fixed with almost the same result as before, but a little more colour. On drying the plates, however, I found the image appeared more clearly, and the plates generally darkened in colour. Still, how ever, they lacked density, and I set about-trying to intensify. I tried chloride of mercury and ammonia, chloride of mercury and cyanide of silver, Edwards’ intensifier, and other things, but all to no purpose. My plates seemed useless. In my despair I did what the doctor told the miser to do, who asked a physician in a friendly way what he should do for a bad cough. I took advice. I went to the nearest photographer— our worthy secretary—and into his sympathetic ear I poured forth my sorrows. He looked at the plates I showed him (I may tell you I had not then discovered the mistake I had made), and he told me I had evidently not followed Capt. Abney’s formula. However, after a good many attempts to impart density to the pictures, he tried re-developing with pyro, with the result of making the plate a deep brown all over, leaving the image, however, as before, perfectly clear and distinct. The applica tion of hypo, however, brought it back very much to its original state, and left us as much puzzled as ever ; and after taking up a great deal more of his valuable time than I had any business to do, I left him. Discouraged, but not yet beaten, I went home and worked away on the plates until I succeeded in destroying all I had already done. The most hopeful plan now seemed to be the application of a developer, and after a few more trials I at last succeeded in getting something like what I wanted, and I now propose to show you the results. Unfortunately, before I hit on this plan of re-developing, I had concluded that the plates were worthless, and accordingly I left them lying about in the dark room till I should find time to clean them, and so they got contaminated with chemical im purities, hence the many imperfections you will observe in the plates. Imperfect as they are, however, they will be sufficient to give you some idea of the capabilities of the process, and enable you to judge of its value. No. 1 was printed to correct depth, dropped into an old and almost exhausted acetate of soda toning bath, and then fixed with hypo. Image disappeared, but re-appeared, and darkened on drying. Result of the picture is quite distinct, full of detail, perfectly transparent, but so thin as to be almost invisible by transmitted light without an opaque background. It shows a a pale yellow in the lantern in a disc of two feet diameter. No. 2, printed till half tones lost and high lights darkened. Toned in strong fresh borax toning bath, and fixed. Picture I disappeared, but came out again on drying. Result—picture perfect but transparent, and almost invisible, without opaque background, shows very pale brown, with tint of purple in lantern. No. 3 printed to full depth. Toned in very strong borax, bath warm, then put into developer—sat. sol. sulph., 1 drachm; oxalate potassium, 3 drachms; bromide potassium, 3 grains; water, 1| ounces; sol. cyanide silver, a few drops. There it remained till the sky darkened, and I then fixed it. As usual, the picture faded out. I then dropped into the developer again, when the image immediately began to come up strongly, and I allowed it to remain until it came up fully. Unfortu nately, the sky stain came up also. Result—the picture is vigorous and full of detail and contrast, shows well by trans mitted light with or without a background, and in the lantern is of a fine dark purple. No. 4 was very much under-printed, dropped into same deve loper as No. 3, till sky showed signs of darkening, then put into toning bath four minutes, and fixed. As usual, image dis appeared. Dropped into developer, image re-appeared very slowly. Strengthened bath by addition of half-ounce ferrous oxalate ; image came up a little quicker ; added more ferrous oxalate till image completely up. Result—picture dense, but wants contrast, evidently foggy. In lantern shows rich brown, but very far from being a brilliant picture, the high lights being dark and foggy. No. 5, printed a little over full depth, toned in nearly exhausted toning bath, developed as No. 3 without cyanide, fixed, and re-developed. Result—a good picture, shows well by transmitted light, full of contrast and detail, and in lantern shows of a fine rich brown, but exhibits evident traces of over-exposure in the high-lights. No. 6, same as No. 5, but with cyanide of silver and double allowance of bromide in the developer. Result—fine, but much over-developed. Shows too dense with a background, but would do well for a window transparency ; shows splendidly in lantern with small disc at a short distance. No. 7, printed to full depth, toned in strong new borax bath, developed as No. 6, but with double allowance of cyanide, fixed, and re-developed. This shows the result I have been aiming at —clear glass in the high-lights, fine half-tones, and great depth in the shadows—withal, perfect transparency, and a fine purple tone, it shows well either with or without a background, and in the lantern. No. 8 was over-printed, treated as No. 7, but plate being spotted, was not carefully treated. Except over-printing and spots, the result is very similar to No. 7. No. 9, very much over-printed, toning bath very weak, treated as No. 8. Result—-a fine rich brown, but very much over-exposed and over-developed. The result of these experiments, though not quite conclusive, seems to be that plates coated with gelatino-chloride of silver emulsion are exceedingly suitable for transparencies if printed to full depth, toned with gold, treated with weak solutions of ferrous oxalate, with the addition of cyanide of silver and bromide, fixed with hyposulphite of soda, re-developed as I have described in Nos. 6 and 7. Their greatest advantages seem to be that the whole process of forming the image is perfectly under control in every stage, while the vigour and transparency of Nos. 6 and 9 seem to leave little to be desired, and the operation after printing may be carried on in strong gas-light, as all my experiments were. ON IMPROVEMENTS AND NEW APPLICATIONS OF THE PLATINOTYPE PROCESS. BY HERBERT B. BERKELEY.* Very excellent paper transparencies may be produced by printing on a specially-prepared platinotype paper, in which the image is carried in the shadows through to the back of the paper in the manner just referred to. The print, when thoroughly dry, is treated with paraffin wax by immersion in a dish heated to a sufficient high temperature to make this wax fluid. After a short time the prints may be taken out and placed between blotting-paper, over which a hot flat-iron is passed. Paraffin is preferable to bees’-wax only on account of its stable character. The transparencies so produced are remarkably vigorous, of fine detail and gradation, and of a rich brown-colour. They may be used for reproducing negatives. * Continued from rage 151.
- Aktuelle Seite (TXT)
- METS Datei (XML)
- IIIF Manifest (JSON)