A Guide to Photography

Front Cover
1845
0 Reviews
 

What people are saying - Write a review

We haven't found any reviews in the usual places.

Other editions - View all

Common terms and phrases

Popular passages

Page 24 - ... silver are thus thoroughly dissolved, and may now, with the hyposulphite, be entirely removed, by soaking in water and pressing in clean white blotting-paper, alternately; but if time can be allowed, soaking in water alone will have the effect in twelve or twenty-four hours, according to the thickness of the paper. It is essential to the success of the fixing process, that the paper be in the first place thoroughly penetrated by the hyposulphite, and the sensitive matter dissolved; and next,...
Page 42 - First, a mode of fixing and strengthening pictures by oxidation : — The impression being obtained upon a highly polished plate, and made to receive, by galvanic agency, a very slight deposit of copper from the cupreous cyanide of...
Page 22 - ... gallo-nitrate; in that space of time it absorbs sufficient to render it exquisitely sensitive. The excess of gallo-nitrate must immediately be washed off by drawing the paper gently several times under the surface of water, which must be perfectly clean ; and being thus washed, it is finished by drawing it through fresh water, two or three times, once more. It is now to be dried in the dark, in the manner described in 7, and when surface-dry, it may either be placed, while still damp, in the...
Page 42 - ... until the light parts assume a pearly transparent appearance. The whitening and cleaning up of. the picture, by this process, is far more beautiful than by the ordinary method of fixation by a deposit of gold.
Page 43 - In one instance a clear and beautiful ruby colour was produced, limited in a well-defined manner to the drapery, while all other parts were green. To succeed well in the first process, viz. that for fixation and the production of the pearly appearance, the impression should be carried as far as possible without solarization, the solution...
Page 43 - ... of soda should be pure, and free from the traces of sulphur*, the plate should be carefully washed with distilled water, both before and after it receives the deposit of copper, — in fact, the whole experiment should be neatly performed, to prevent what the French significantly call laches upon the plate, when the copper comes to be oxidized.
Page 41 - It is sufficient to place the plate on a support, fig. 64, or fig. 66, g, and pour upon its surface a sufficient quantity of the salt of gold that it may be entirely covered, and heat it with a strong spirit-lamp ; the picture will be seen to brighten, and become, in a minute or two, of great force. When this effect is produced, the liquid should be poured off, and the plate washed and dried. " In this operation the silver is dissolved, and the gold precipitated upon the silver and mercury, but with...
Page 22 - As soon as the paper is wetted with the gallo-nitrate, it ought instantly to be removed into a dish of water; five or ten seconds at the most is as long as it is safe at this stage to leave the paper to be acted upon by the gallo-nitrate; in that space of time it absorbs sufficient to render it exquisitely sensitive. The excess of gallo-nitrate must immediately be washed off by drawing the paper gently several times under the surface of water, which must be perfectly clean ; and being thus washed,...
Page 21 - The paper is now to be dried; but while wet, do not on any account touch or disturb the prepared surface with " blotting-paper," or with anything else. Let it merely be suspended in the air, and, in the absence of a better expedient, it may be pinned across a string by one of its corners. When dry it may be smoothed by pressure. It is now
Page 21 - Holding by the upturned margin, the paper is to be gently drawn along the surface of the liquid until its lower face be thoroughly wetted on every part ; it will become plastic, and in that state may be suffered to repose for a few moments in contact with the liquid; it ought not however to be exposed in the iodine dish for more than a minute altogether, as the new compound, just formed upon the paper, upon further exposure would gradually be redissolved. The paper is therefore to be removed, and,...

Bibliographic information