BTZS Film Tubes and pre-soakgreenspun.com : LUSENET : Large format photography : One Thread
I recently purchased the BTZS Film Tubes. Neither the directions nor Darkroom Innovations' web site mentions pre-soaking the film with water before developing. I've always pre-soaked when using open tanks. Should I pre-soak with the BTZS Film Tubes - and, if so, how?
-- John Cooley (firstname.lastname@example.org), January 05, 2002
I've used the tubes with Ilford films (mostly HP5+) and with T Max films for years. I've never pre-soaked any of them. I think some companies (e.g. Ilford?) actually recommend that you not presoak their films. If you really wanted to presoak with the tubes you could do it by loading the film, putting water in the tubes, then dumping the water and adding the developer (all in the dark of course) but that would sure complicate your life. The other way would be to do the soaking in a tray and then load the film in the tubes but that would be very hard to do if you were trying to keep track of different developing times for different sheets of film. Pesonally I'd forget about presoaking and just enjoy the convenience of the tubes.
-- Brian Ellis (email@example.com), January 05, 2002.
I remember reading somewhere that Ilford film actually contain a wetting agent in the emulsion that is supposed to assist in even wetting at the start of development, exactly what a pre-soak is suppose to help accomplish.
But, I could be wrong.
I use HP5+, and develop in homemade tubes. Never had a problem. TMax made me a bit nervous, however, since when you dumped out the developer afterwards, it was a lovely dark color - but it didn't affect the development...
-- Ken Miller (firstname.lastname@example.org), January 06, 2002.
I use Patterson tanks to develop roll film and I presoak (TMX, TMY, p3200) because I believe that the replacement of the water in the emulsion by the developer is slowed down enough to make up for the time differential in pouring the developer into the tank. For 4x5 and 8x10 I use BTZS tubes. The developer probably touches all parts of the emulsion in less than 1 second so I don't pre-soak.
-- jeff schraeder (email@example.com), January 07, 2002.
For what it's worth: I've pre-soaked roll film in water w/ 1 drop of Photoflo for 1 min. @ 68 degrees. Dump and Develop @ 68 degrees also w/ 1 drop of Photoflo. Fix per directions. The reason is not so much as to get the film emulsion "ready to develop" but more to stabilize the temperature of the tank. The Photoflo prevents air bells. This procedure has worked for me for the past 18 years. Last year I got into 4x5 and followed the same procedure using a Unicolor drum and motor base for film processing. Results: Perfect negs every time. BTW the pre-soak dump water color is the anti-halation backing coating washing off. Agfa's is a really dark puke green color. YUM!
-- Steve Feldman (firstname.lastname@example.org), January 08, 2002.
I have used BTZS tubes with 4x5 TMX and TM-RS developer and others for years. If your concern is evenness of development or steaking, etc., there is no need for pre-soak with these tubes - even when development is as short at 3 minutes. Reason is both in the design and the constant agitation process. Just make sure that you agitate fully for 15 seconds before you put the tubes in the bath, then rotate them constantly and with an irregular pattern back and forth. These tubes are simple, reliable, and perfect for Zone System, individual control development. With the BTZS testing, I can develop for partial zone readings against the software graph (Zone +1.3, etc.) I have also found that testing does not have be repeated. Once you get your oen numbers for film/developer combination, they stay the same unless you change your procedures and patterns for agitation. Just pick up the phone and call Darkroom Innovations, now View Camera Store. They go out of their way to be helpful, and they know large format. Hope this helps.
-- D. Meriwether (email@example.com), January 11, 2002.
ABC+ pyro (a/k/a rollo pyro) from the Formulary requires a presoak with a dilute base solution. When I use my home made BTZS tubes, the presoak solution usually does not get to all of the film base and this can cause streaking (I don't know why, but it's annoying; I use 8x10 Tri-X and T-Max 400). For the presoak, I load film, put in the solution, cap the tubes, turn on the light and start the tubes a spinnin'. After a few minutes, it's lights out, open the tubes, pull the film half out and slide it back in - so the solution can reach the film base - recap, lights on and spin for a few more minutes of presoak. Then dump the presoak and put in the ABC+ developer.
Needless to say, it's a big pain in the rump. I've switched to liquid PMK (which is a tray process) for pyro negs.
For normal development, I use Xtol in the tubes and there's never a problem with the solution getting to the film base. I suspect Xtol has a greater viscosity (or maybe lower viscosity - what I mean is that it's "more slippery" than plain water) that permits it to get to the film base.
-- Richard Lingg (firstname.lastname@example.org), January 11, 2002.