Archived posting to the Leica Users Group, 2000/03/01
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]At 09:36 PM 29/02/2000 +0000, Johnny Deadman wrote: The less rapid uptake of dev into emulsion is supposed to suppress >contrast (= need to extend dev time for equivalent gamma). It does and it doesn't! Depends on the film. A while back Phil Davis published a comprehensive report on this. With some films, presoaking required extending the development time. Surprisingly with some others, shortening the development time was needed. Go figure! Furthermore, with other films there is no appreciable difference in development time required whether or not a presoak is used. So, if you are going to presoak, it is a good idea to run some fairly careful tests with your favourite emulsions, under controlled conditions to find out exactly what kind of adjustment will be required when presoaking is used. _ [o] -GH