de Cezar Popescu | apr. 1, 2012 | Miscellaneous
This developer gives negatives of soft gradation with maximum detail in the shadows. Development is slow, but the speed may be modified by altering the dilution. Stock solution Ingredient Quantity Mix chemicals in order. Metol 3 grams Sodium sulfite crystalline 25...
de Cezar Popescu | apr. 1, 2012 | Desensitizers, Miscellaneous
Desensitizing is a process whereby the sensitivity of a plate or film is depressed, so that the development can take place by a brighter darkroom illumination. At the present time (1943) the following desensitizers are available: [wptabs type=”accordion”...
de Cezar Popescu | mart. 14, 2012 | Miscellaneous
These chemicals, which should be added to the developer in quantities from 0.1–0.2 grams per litre, impart to the developer valuable additional properties. They have strong anti-fogging properties. With development papers, developer improvers produce purer and deeper...
de Cezar Popescu | mart. 14, 2012 | Miscellaneous
When the developer is prepared with tap water, the solution usually appears cloudy, which fact is due to the lime salts of the water combining with alkali and forming a precipitate. This turbidity has no effect on the properties of the developer, but if the lime...
de Cezar Popescu | nov. 16, 2011 | Miscellaneous
The skin troubles (similar to eczema) attributed to metol are exclusively due to an impurity (NN—dimethyl paraphenylene diamine) and do not appear to have been experienced with metol of French make. —L.P. Clerc, “Photography—Theory and Practice”, 2nd edition, Pitmann...
de Cezar Popescu | nov. 8, 2011 | Miscellaneous
It may be laid down that there is no really non-actinic illumination in the true sense of the word; that is to say, that there is no light, whatever may be its spectral distribution and however weak in intensity it may be, which will not fog a photographic emulsion if...
