В принципе для того же, но по поим наблюдениям результат немного лучше чем при использовании лимонной кислоты. У меня, по крайней мере на бумаге Canson и Fabriano, уксус не приводил к изменению цвета. Кроме того нужно "проявлять", т.е. минут на 5-10 оставить плавать лицом вниз в ваночке с уксусом, сразу после экспонирования, а потом промывка. В книге предлагается от 7% до 1% раствор. Я пользуюсь 1%.
Вот что говорит по этому поводу Его Величество интернет
http://unblinkingeye.com/Articles/3CG/3cg.htmlI also add a little vinegar to the first wash, or soak, to further increase speed and to smooth out the highlight tonality. A word of caution: the addition of vinegar to the wash water will also cause some of the blue to float and it will reattach to the tray and everything else. To minimize the problem, use a fresh bath of vinegar with water for each print. In addition, the print needs to be immersed in it in one smooth motion or edge lines could form.
http://www.ephotozine.com/techniques/viewtechnique.cfm?recid=155Wet processing and contrast control
The exposed paper can be processed most simply with gently running tap water for at least twenty minutes; alternatively, several static baths may be used. The water should not be significantly alkaline, which destroys Prussian blue, but preferably have a pH below 7. It is important to avoid using 'hard' water, because calcium ions interfere.
However, a stronger result altogether can be obtained by processing first in a 'development' bath of very dilute mineral acid: a deeper maximum density is obtained with a long printing exposure range of about 2.4. Hydrochloric acid or nitric acid are best, at a strength of about 1%, i.e. the usual concentrated acid is diluted about 100 times (10 cc to a litre of water): be sure always to add the acid to the water, not vice versa, and take precautions to protect your eyes and skin and lungs from the concentrated acid. In the interests of safety, a lesser dilution of a more dilute stock solution of acid may be preferred. The diluted 1% bath is not dangerous; but if you baulk at using these mineral acids, then dilute citric or acetic acid (vinegar) will also work to some extent. The print need remain in this bath for no more than about half a minute. By varying the acidity of this processing bath, considerable control of the contrast may conveniently be achieved at the development stage. The development bath tends to accumulate Prussian blue, which will eventually begin to stain the paper, so it should be replaced after a few prints have passed through; typically, 1 litre will process five to ten 10 x 8 inch prints.
