The Dictionary Of Photography

A True Historic Record Of The Art & Practice Of Photography 100 Years Ago.

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Photography in Natural Colours
C.
Water           ... ...... ...... 15 c.cm.
Potassium bromide            ... ...         ... 035 gm.
Sodium chloride ... ... ... ... 035 ,,
A is divided into two parts, one poured into B, the other into C, well mixed, and then B added toC at 35o-40o C.
II.
A.
Water ...............    300 c.cm.
Gelatine ...............      10 gm.
Silver nitrate ... ... ... ...        6 ,,
B.
Water ... ... ......        ...    300      c.cm.
Gelatine ...... ......        .,.      20      gm.
Potassium bromide... ... ...        ...        2*4 ..
Sodium chloride ... ... ...        ...        1*5 ,,
Mixing temperature, 350 C.
The exposure for sunlight for the bromide plates with a width ol 03 to 05 mm. slit is one minute, but with a wide open slit and a condensing lens ten to twenty seconds. For developing Valenta used -
A.
Pyrogallol ... ... ... ... .
Water           ... ..........
Nitric acid ...... .......
B.
Potassium bromide... .......
Water           ......
Ammonium sulphite Ammonia (sp. gr. 0*91)
For 2-3 parts of B are mixed with 1 part of A and 12-14 parts water. Valenta has also used the following modification of Lumiere s developer: -
A. Water           ... ... ... ... ... 100 c.cm.
Pyrogallol ... ... ... ... ... 1 gm,
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