Archived posting to the Leica Users Group, 1998/11/05
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Very interesting George. I am sure you are correct as I have not tried pre-washing yet. I would have assumed that pre-washing would have done just the reverse of what you state, allowing the developer to act faster vs. slower. What has been your experience in the development time-reduction, say at 72 degrees(%)? Thanks for your coments. Bob Bedwell Greensboro, NC << At 05:13 PM 04/11/98 -0700, you wrote: >The important thing here is to "PREWASH" the >film for 4 minutes in plain water. The higher speed films tend to have a >antihalation layer that slows down processing. The prewash removese this. > Careful. Prewashing requires a change in development time to compensate for the additional time required for the developer to reach the emulsion in the prewet film. If the film is dry, the developer gets to work right away on the emulsion, reducing the silver ions. With prewet film, there is an increase in the amount of time required to get the developer into contact with the film. If you prewet/prewash films, you will have to conduct your own tests to determine the additional amount of time required to bring about development to completion. >>