The Dictionary Of Photography

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

Home | About | Photography | Contact

Ammonium bromide          ... ... ... I oz.
M          carbonate ... ... ... I ..
Distilled water, to............ 25 ozs.
Mix in equal parts. The following simpler developer is now suggested: -
Sodium carbonate ... ... ... ... 2 ozs.
Water, to ............... 40 ,,
For use, mix one part of each, and add one part of water. For average negatives, use one part No. I., one part No. II., one part water. Whatever variations are made, make up always to bulk three parts, by adding or omitting water. If required to work slower, use less No. II., or make up the stock solution with less ammonia. If harder effect (more contrast) be desired, use less No. I.; if softer results (less contrast), use more. It may happen that we find that the print when finished is too dark, and has been over-printed. The question is how to reduce it. It is questionable whether it is worth the trouble, whether it is not almost as easy to make a fresh print altogether. The old ferrid-cyanide and hypo reducer has been suggested for gelatino-chloride prints ; and reduce them it will, so energetically, even in weak solutions, that its action may be uncontrollable. Haddon sug-gested a mixture of sulphocyanide and ferridcyanide, and this certainly acts more slowly and evenly, but the sulphocyanide makes the gelatine very soft. Valenta suggests, however, a