Suche löschen...
The photographic news
- Bandzählung
- 29.1885
- Erscheinungsdatum
- 1885
- 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-id1780948042-188500006
- PURL
- http://digital.slub-dresden.de/id1780948042-18850000
- OAI
- oai:de:slub-dresden:db:id-1780948042-18850000
- Sammlungen
- Fotografie
- LDP: Historische Bestände der Hochschule für Grafik und Buchkunst Leipzig
- Bemerkung
- Seite I-II fehlen in der Vorlage. Paginierfehler: Seite 160 als Seite 144 gezählt.
- Strukturtyp
- Band
- Parlamentsperiode
- -
- Wahlperiode
- -
- Bandzählung
- No. 1380, February 13, 1885
- Digitalisat
- SLUB Dresden
- Strukturtyp
- Ausgabe
- Parlamentsperiode
- -
- Wahlperiode
- -
-
Zeitschrift
The photographic news
-
Band
Band 29.1885
-
- 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 29.1885
-
- Titel
- The photographic news
- Autor
- Links
- Downloads
- Einzelseite als Bild herunterladen (JPG)
-
Volltext Seite (XML)
102 THE PHOTOGRAPHIC NEWS. [FEBRVARY 13, 1885. Abstract of a paper read before the Photogrophic Club. + Continued from page 91. AN IMPROVEMENT IN LENS SCREWS. BY GEORGE SMITH.* TRE Rev. A. Corbet’s suggestion to turn off, in a lathe with an eccentric chuck, a portion of the screw-thread on both lens and flange, struck me as an excellent idea ; the only difficulty being that of gaining access to a lathe fitted with such a chuck, I asked myself whether it could not be easily done by hand with a file, and at once set to work and did it. It is simplicity itself, and answers perfectly. First screw the lens fairly home in its flange, and make a mark top and bottom, or if you like to take a little more trouble, three equidistant marks on both lens and flange; now file away all the thread in the intervening spaces up to (say) a quarter of an inch from each mark ; do this to both lens, mount, and flange, preferably leaving a little greater length of thread on the flange than on the lens mount. I have found it a good plan to make a distinct black mark on the lens mount, at the top, and a black line on the inner edge of the flange, show ing at a glance the exact spot at which to enter, and the distance to be travelled to completely fix the mount in the flange. three plies of cotton-cloth, a pipe at the lowest end conducting any spilt bath, or splashes ot toning solution, into large glazed earthen pans, in which a quantity of sulphite of iron is placed. After the prints are toned, they are placed in trays of water ; this and a subsequent washing are also thrown into the glazed pans ; these, when filled, are allowed to stand for two days, when the clear water is drawn off, leaving the gold residue at the bottom. From time to time it is lifted and dried in the same manner as the chloride. I have found it pay to provide the toners with thick cotton aprons, which are burnt after a certain time, and the gold which has got on them from splashes when toning, recovered. Previous to erecting the trough I have described, the dishes for toning were placed on a bench eight feet by two feet. When removing this, more from curiosity than anything else, I reduced the whole bench to ash, and received from the assayer the sum of ft 11s. 7d. as the value of gold it had contained. I now come to the last operation, viz., fixing the prints ; and a most important quantity of silver is recovered from the hyposul phite of soda solution in which the prints have been fixed. In my practice the fixing of the prints take place in shallow slate trays, fixed permanently inside a long trough ; each tray is pro vided with a plug, and the waste solution runs off by a pipe into the depositing troughs, which are placed in the open air. Two of these are used ; while one is filling, the other has time to allow the sulphide of silver to settle at the bottom. Wooden spiggots are placed in these troughs about ten inches from the bottom, to allow’ the clear liquor to run off. For precipitating the silver I use strips of zinc suspended in the liquid, and also a small quantity of liver sulphur. This residue is a very valuable one, and I understand many photographers do not know this, as many throw it down the sink. From the £720 worth of silver used, I recovered the sum of £193 16s. 4d., this giving a total of £476 7s. 3d. recovered in the shape of residue from £720 worth of silver nitrate used, and I had still in hand of the £720 silver bath to the value of £25 10s. Of gold I used £274 worth ; I recovered £101 14s. 3d. Another valuable residue is that from the fixings of gelatine plates. I regret I am unable to give exact proportions on this matter at present. The assayer's charge for reducing the above value of residue was £24 10s. 9d., and I have never been able to do it so cheaply myself. I shall be glad if these notes have the effect of inducing others to save systematically their gold and silver “ wastes.” ON THE RAPID PRINTING PAPER. BY LEON WARNERKE.t NeXT follows the development of the image. All manipula tions with this paper can be carried on in a room illuminated with orange or yellow light. I am personally in favour of yellow paper, either for a lantern or for a window. Canary paper answers very well. It can be prepared by treating ordinary white paper with any sort of lead. When dry, immerse it in a solution of bichromate of potash, and wash in water. It may be said that generally a great deal more light can be allowed than for gelatine bromide plates. The paper, when removed from the printing frame, must be soaked in cold water. Some prefer to put it immediately in the developer without wetting ; but for my part 1 always prefer, whether an emulsion be on glass or paper, to soak the film first in water. Development can be effected with ferrous-oxalate, ferrous- citrate, or hydrokinone developers, each producing a different tone. 1. Pirvous-Oxalatc Developer. A.—Potash oxalate ... Ammonia bromide Water ... B.—Iron sulphate Water ... 25 parts or 2 J ounces 1 part or 48 grains 100 parts or 10 ounces 10 „ 1 ounce 150 „ 15 ounces Adding a small crystal of citric acid. These two solutions are mixed in equal proportions, and the mixture may be diluted with water for warm tones and dense negatives. 2. Fcrrous-Citratc Developer. A.—Citric acid 200 parts or 4 ounces Ammonia carbonate . .. 100 „ 2 „ Water .. 500 » 10 » B.—Iron sulphate ... .. 100 „ 1 ounce Water .. 500 „ 5 ounces Adding a small crystal of citric acid. C.—Common table salt .. 5 parts or 1 ounce Water .. 100 „ 20 ounces A and B are mixed in equal proportions, and a few drops ot C added, according to the exposure given and tone of the print desired. Ferrous-citrate develops the slowest, and produces generally the warmer tone. 3. Hydrokinone Developer. A.—Hydrokinone Alcohol B.—Potash carbonate ... Water C.—Common table salt Water 5 parts or 24 grains .. 100 ,, 1 ounce .. 20 „ 90 grains .. 100 „ 1 ounce .. 5 „ 24 grains .. 100 „ 1 ounce To form a developer, mix 10 drops of A, 5 to 10 drops of B, 1 to 3 drops of C ; water, 1 ounce. A short time after the exposed paper is immersed in the de veloper, the image begins to appear. If the exposure be short, the colour of the image will be black ; but the longer the expo sure, the redder is the first image. The development is continued until all details arc out. A properly exposed print should per mit sufficient details in the high lights to be seen before the deep shadows become too heavy ; but in the case of a very intense hard negative it will require some practice to adjust properly the exposure and the developer. With such negatives a normal developer will give hard and very dark prints ; but dilution with water, in proportion to the density of the negative, will over come this difficulty. It will also be found in practice that with some sort of nega tives a warm tone is not easily obtained. Clear and rather weak negatives are preferable for this paper. The ferrous-citrate developer very often will give a warm tone, when oxalate will not. The ferrous-oxalate developer is quicker, but, being de composed by the action of the atmosphere, it cannot be used for developing longer than from twenty to thirty minutes, inde pendently of the number of prints immersed. Ferrous-citrate keeps much better, and can be used for hours, therefore it will be found more convenient when many prints have to be de veloped. Hydrokinone gives very warm tones : it is very economical, notwithstanding the cost of the salt; but being used very diluted, it is cheaper than iron. The only objection I found was, that it is very soon discoloured, and if the develop ment for this or any other reason is prolonged, there is the danger of staining the paper. The ultimate tone of the print can be modified by gold toning—warm tones cannot be got easily if the developed print is of a blue or slate colour. This is the reason that it is useful to have in readiness more than one developer, and to use them according to the nature of the negatives. Lastly, I may mention that the relative proportions of the salt forming the developer has considerable influence on the developed imago. It will bo out of place in this paper to dwell longer on this important subject; but I must refer persons interested to the excellent
- Aktuelle Seite (TXT)
- METS Datei (XML)
- IIIF Manifest (JSON)