Archived posting to the Leica Users Group, 1998/11/05
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Concerning the comments about prewash of film before development. Would all of you who advocate this and those who are posting reasons why or why this is or is not a good idea, please provide some sources for your information? Additionally, which specific films are you talking about, or are you saying the reasons are a general rule of thumb. 20 years of daily processing, of every conceivable film, in roll and sheet, including Minox, 110 sizes, Cirkit, Aerial and Banquet, perhaps 30,000 or more rolls so far, in deep tanks, roll film tanks and troughs do not indicate these problems of how fast developers work with wet Vs dry materials. I would like to see substantive proof that it makes a difference. I tested this idea more than a decade ago with different emulsions and I saw no evidence that there is any concern. The last test was to eliminate air bells when the burst system went down, and pre wetting was one solution to eliminate the problem. Absolutely no substantial difference in negative density either way. It was not generally reported in the literature and I wonder. Perhaps it might be happening to some, but it may also be something else altogether. The only film I pre wet these days is litho materials that I use for making presentation slides. Pre wetting helps eliminate the air bells to some extent. RM