Suche löschen...
The photographic news
- Bandzählung
- 6.1862
- Erscheinungsdatum
- 1862
- 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-id1780948042-186200003
- PURL
- http://digital.slub-dresden.de/id1780948042-18620000
- OAI-Identifier
- oai:de:slub-dresden:db:id-1780948042-18620000
- Sammlungen
- Fotografie
- LDP: Historische Bestände der Hochschule für Grafik und Buchkunst Leipzig
- Bemerkung
- Seite 1-72 fehlen in der Vorlage. Vorlagebedingter Textverlust.
- Strukturtyp
- Band
- Parlamentsperiode
- -
- Wahlperiode
- -
- Bandzählung
- No. 205, August 8, 1862
- Digitalisat
- SLUB Dresden
- Strukturtyp
- Ausgabe
- Parlamentsperiode
- -
- Wahlperiode
- -
-
Zeitschrift
The photographic news
-
Band
Band 6.1862
-
- 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 6.1862
-
- Titel
- The photographic news
- Autor
- Links
- Downloads
- Einzelseite als Bild herunterladen (JPG)
-
Volltext Seite (XML)
AUGU 382 [August 8,1862. THE PHOTOGRAPHIC NEWS. board on the stove, by which means the cement becomes fluid. The fractured surfaces, if not thoroughly clean, must be well washed, first with soap and water, and afterwards with alcohol, but if the vessel has been newly broken it is not necessary to take this precaution. The edges of the broken parts are next warmed, aud then the glue is applied ; the pieces are now brought into apposition and kept there until the glue has thoroughly concreted, which will take place in a few days. All. the articles used in this cement have to be the purest and best of their kind in order to succeed in its preparation satisfaetorily ; but it can certainly be relied upon when so prepared.—Humphrey’s Journal, • A NEW RAPID DRY PROCESS. BY E. BORDA.* Mb. Editob.—As you no doubt inferred from my last comuni- cation to you, I was far from satisfied with the instantaneity of the tannin plate, developed after soaking it in warm water. It was a great step forward, rendering the tannin plate as quick as the generality of wet plates, and its usefulness must have been felt by many in more than one respect: to me it was an auxiliary in one way, of a stimulant, in another; an auxiliary by enabling me to bring out of a tannin plate, not sufficiently exposed for ordinary development, more details in the shadows, avoiding at the same time the solarization near the high lights, which takes place in a view offering great contrasts, when the exposure is sufficiently prolonged to secure details in the shadows; a stimulant, by leading to the supposition that during the shortest exposure, the light had likely performed its share on any sensitive film, and that to render the film sufficiently penetrable to the developer was the true way to obtain a quick dry plate. My last experiments seem to confirm this hypothesis, although contrary to the conclusion of Mr. Sutton, that free nitrate of silver in the pores of the collodion was necessary ; Mr. Sutton may be correct that far, that such condition may lead to an instantaneous dry plate, but I do not believe it to be a sine qua non. I am indebted to Mr. H. T. Anthony for a suggestion which has given mo results in rapid dry plates, far beyond what I have been able to obtain with warm water. Mr. Anthony, amongst numerous valuable hints which he has freely and generously given to me, stated that some years ago he had submitted a dry plate to the action of ammonia, and obtained with it a good negative with very short exposure. It was shortly after the warm water process was made public that Mr. Anthony suggested to me to try the warm water, and fuming by ammonia combined. I first tried the fuming alone, and on a tannin plate; the acceleration was remarkable. I obtained with it, at the start, quicker plates than with warm water, by fully one-third. I soon ascertained also that it was not necessary to fume the plate before exposure, but merely before development; rendering the process more valuable for field work, as it is doubt- ful whether a plate fumed with ammonia would keep; but when 1 proceeded to add the acceleration by warm water to the fuming, I was disappointed. Both had an accelerating effect, sepa rately, but the result of their combined actions was not the same of the two; nor indeed could I detect auy acceleration on the fumed plate, by developing it warm. The film covered with tannin became very tender, and had a tendency to fog, which any amount of acid did not appear to check, and as far as my own work was concerned, I substituted the fuming to the warm water development, when I desired to accelerate a plate, as more controllable, simpler, and requiring less ex posure. I merely speak of results in my hands, and would much rejoice to know that others are trying it thoroughly. While making the experiments above mentioned, it happened several times that a tannin plate, from which the free nitrate could not have been washed off thoroughly, gave mo a faint image of the high lights, when soaked in warm water, after fuming with ammonia, and before any developer was used. The quantity of free nitrate must have been excessively small, for I wash my plates very carefully, and am not troubled with the spots arising from an imperfectly washed plate. I would have been tempted to attribute it to some other cause, if it had invariably occurred; but it was only occasionally, some of the plates not giving the slightest trace of an image before the developer with silver was poured on. Nor could it be caused * From the American Journal of notojraphy by over-exposure, the same plates failing from under-exposure, as I was trying to obtain negatives by very short exposure, and with a supposed combined acceleration, resulting from joined actions of water and ammonia on the film. This fact might wu- firm Mr. Sutton’s theory, when removing from it its objectio- able conclusion, that the free nitrate of silver in the film iste only mode of securing the quick dry plato. Is it not possible that, by leaving in the film a certain proportion of free nitrate of silver, such as is left on a Fothergill plate, an imago can bo obtained sufficiently intense, with the addition of fuming with ammonia and warm water, with very little development, or no development at all ? The fuming with ammonia, like the warm water, is to bo regulated by experience, aud it is impossible to give any more than general rules. Every operator must depend a good deal on his own judgment. The strength of the ammoniacal solu tion itself varies very much, as well as the size of the box in which the fuming takes place. For a tannin plate, exposed fifteen to twenty seconds, with one-eighth inch diaphragm, by a clear day (I allude to landscape- photography), I fume the plato from five to six minutes, in a box about two cubic feet in capacity; using one ounce of concentrated solution of ammonia, placed in a flat dish in the bottom of the box. By a little fon at the top, moved by a crank at the outside, I equallize the amount of ammonia through the box. The more the plate is fumed, the more citric acid must be used in the developer, to prevent the formation of a deposit which ruins the negative. I even fume plates exposed two, three, and occasionally five minutes, with the view of bringing out details in the shadows. When the plate is almost sufficiently exposed for ordinary deve lopment, I regulate the fuming accordingly. I sometimes con fine it to one minute, using one ounce of the concentrated solu tion, diluted with two or three times its volume of water, or some ammonia solution which has already been used for the same purpose, and has lost much of its strength. When the plate has been but shortly exposed and fully fumed, it develops blue black, and the more it has been exposed the more purple it gets; when very purple, care must be used to not over develop. 'With distant hills a couple of minutes exposure, and pretty good fuming, is preferable, in order to secure good clear distances. If there is no great distance, and no bright sky likely to solarize the top of trees, &c., more exposure and less fuming is preferable ; the older the collodion the less solarization is to fear. When I wish to secure clouds, I reduce the exposure to a few seconds, and rely on plenty of fuming and a good dose of citric acid. I never begin to develop a plate (seven by four) with more than one drop of a ten-grain solution of uitrate J silver, and to each drop of silver I use one drop of a sixty-grais solution of citric acid, for a plate fully exposed and not fumed; if fumed slightly, two drops of citric acid; if shortly exposed and fumed fully, five to six drops, and a proportionate quantit, of citric acid for intermediate exposures and fumings. My experiments with fuming did not stop with the tannin plate. I thought it too valuable not to apply it to other pro cesses, and it naturally occurred to me to try some dry process quicker than the tannin: I tried the resin process, and first on its own merits ; I succeeded with it beyond all my expectations, and by a ramble in our mountains, in which I filled every one of my double dry plate holders with a tannin plate and a resin plate, duplicating each view; I ascertained beyond a doubt, that the resin plate was at least twice as quick as the tannin plate: the collodion was the same : the resin plate, with half the expo sure, gave more softness and more details in the shadows. Th 0 fuming by ammonia accelerated the resin plate fully in propor tion, and six to eight seconds gave me a good negative, whero fully fifteen were required with the tannin. With a quarter tube of no diaphragm, I obtained with the resin plate, in one second, a negative full of details in the shadows. I tried tire iron developer with the very short exposure, but it gave only a faint image, while, with pyrogallic acid, a sufficient intensity was easily attained. If I had the proper apparatus, I would try fuming by the gas ammonia as soon as it is prepared, in winch state I imagine that its action is more energetic. , , I have cautioned your readers against jumping too quick 4 conclusions and indulging too readily in the imaginary PoS8eSi sion of a truly instantaneous dry process; to be consistent, cannot give the resin plate fumed by gas ammonia as such, W that it is another great step towards it, I can state positively. my confidence arises from a series of progressive and systems trials conscientiously done. I long to give the inform; 11 through your paper, with the hope that others will take it and impr is duo for I will i process, that fault with sma spots on t fen, but flat fault I collodion ! s a periot fen is jt train of c imll qua fen very Porerful, : lruseaft 1 Wetion i I “fe of dr Markable I feting the Snberubl W merely -yond ter bath ! g be desi "®rounc I V“’the I "more a "oodsid C -“use 6olingt " to pu ghag fBdvsor I tiComme edetend (1 ^Join ,8— jC* ary ’ BNa/gone V Scr rii 18es afi . SA'od ' Mr. । fc Sl 3 I % "tentw 822 5 8" 5- erm 3
- Aktuelle Seite (TXT)
- METS Datei (XML)
- IIIF Manifest (JSON)