Archived posting to the Leica Users Group, 1999/06/03
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Nathan- The reason for the gradual change, as I was told lo these thirty years ago, was to minimize 'reticulation' of the emulsion. I like you wash my film in ambient temperature tap water, and to be honest, the last film I had reticulation with was ektachrome, in an E4 process. It was so long ago I cannot for the life of me remember exactly when! I had for years thought that the improved films might mean improved safeguards against reticulation! I looked into the manual for the Fuji 562B we use for doing C-41. The process actually does not use a water rinse! Three successive stabilizer washes. The last tank is the only one replenished, and it overflows into the first rinse tank, with the second having it's own replenisher supply, it also overflows into the first rinse tank. The book shows a rather wide acceptable temperature range of 78.9 C + or - 3C. The only really critical temp is the developer that is 78.9C plus or minus .3C I would say that if you rinse in three successively clean changes of water, then stabilizer, all at ambient temp, and you get no reticulation, then you are safe with that procedure. The Chromogenic films are handled in our lab exactly like the color, in fact I have run both on the same leader card, side by side, with absolutely no problem. Of all the new chromogenic films, the new Black and Whate + Select from Kodak is the absolute best for printing on color paper, and getting good blacks and white. The Ilford makes a negative that looks like a B&W negative, no masking, and while it is a bear to print on color paper, it looks good on Ilford Multigrade! Treat the chromogenic film exactly like you would any other C-41 when you develop it as the image is dye based and you need the stabilizer - I think it acts as a mordant for the dye, making it stable against dark fading and oxidation bleaching. Dan - -----Original Message----- From: Nathan Wajsman <nathan.wajsman@euronet.be> To: LUG <leica-users@mejac.palo-alto.ca.us> Date: Thursday, June 03, 1999 2:27 AM Subject: [Leica] C41 processing on Jobo >Friends, > >I have a question about rinsing colour negative films. I have just >recently started processing these myself in my Jobo processor, using the >Tetenal kit. The instructions for rinsing state something like 5 mins at >30-40C, then 7 mins at 25-30C, then 5 mins at 20-25C. The times are from >memory, but the principle is that one rinses in progressively cooler >water. My question is: what is the impact on the film of simply rinsing >the same way as B&W film, i.e. in running water from the faucet, which >at this time of year has a temperature of about 16-17C? And is the >impact (if any) different for the chromogenic B&W films like Ilford XP2? > >Nathan > >-- >Nathan Wajsman >Overijse, Belgium > >General photo site: http://members.tripod.com/belgiangator/ >Belgium photo site: http://members.xoom.com/wajsman/ >Motorcycle site: http://www.geocities.com/MotorCity/Downs/1704/ > >