Using BTZS tubes for the first time...and I ended up with some issues.

So, this is the first time that I have reached out to the APUG community in a while, and the first time ever asking a "What is this on my negative..." question. In the past I've been able to figure out solutions to many of the problems that I have run across in the darkroom, but I've just started using the BTZS tubes to develop sheet film and I am wanting to hear from people that have experience with this system or might know what I've screwed up so that I can fix it in my next batch of processing.

So here is the story that goes with the negative. I processed 18 negatives, 3 batches of 6 using the BTZS tubes. In between batches I rinsed out the tubes and tops and they soaked in a running water bath to make sure that they were clean within useable reason. I have on the second and third batch of 6 negatives streaks from developer or something (I'm just assuming developer). What would be a more reliable way to ensure that I do not get these streaks again? Do I need to wash the tubes and tops more thoroughly? Any thoughts?

Thanks for the input.

The best man to answer your question is Fred Newman (fred@viewcamerastore.com) from Dead Link Removed. You can see some of his video on Youtube.

David,

Are you pre-soaking the negatives before you slip them into the tybes?

Ken

Are you leaving the film in the tubes during fix, or taking them out? Also, do you dry them before the next batch or insert the negs while the tubes are still wet?

If there is any water still in the tubes or caps when you insert the next sheet, it may be wetting the film before you add the developer. Acting like a "spot-presoak" it may impact development in that part of the negative. Your example above looks like a streak of liquid running down the film while the tube is standing upright after loading.

I've been using these tubes for 4x5 for awhile and haven't seen anything like this yet. I wash them in hot water after every session and dry thoroughly.

Here are my steps:
- insert film in dry tubes (in dark)
- develop/agitate as recommended (lights on)
- open the tubes and agitate in a tray of stop bath (dim safelight)
- remove film and place in film hangers
- fix in open-top Yankee tank of fixer (dim safelight)
- wash normally in another open-top tank

KenS, no I am not presoaking the negatives. They are going in dry.

I think that I am getting some remnants of water from when I washed the tubes between each round of development. My first (dry tubes) batch didn't show any streaks from that day of developing. The second and third batch did. I agree that the negative looks like it was some sort of liquid streaking down the tube onto the film. I didn't believe that the errant drop of water would effect the development that substantially I didn't think before hand to dry the tubes thoroughly between rounds of developing.

Jimjm, your process is almost identical to mine, minus the later wet tubes. I, too use an old yankee tank and film holder to keep the negs in the fix and wash stage.

I think that when I start the next time I will be sure to use dry tubes to make sure that isn't the problem any longer. If the staining/discoloration persists I will at the very least know that it wasn't the wet tubes.

A question still bothers me- how can a drop of water effect development that much? Wouldn't it just become diluted into the developer when I began agitation?



Thank you all for the replies.

I'm guessing that any drops of water in the tubes or on the threads may drip down onto the film before you start development. The longer it takes to start the developer agitation, the more time that water has to soak into the film.

One of the supposed benefits of presoak is that it allows the developer to be absorbed into the emulsion quicker. If part of your film is already wet, then the action of the developer may be increased in that area. This may have a more noticable impact especially if your development times are short, like 5 or 6 mins.

I'm just speculating based on what your negative looks like, but it seems like a feasible cause.

Good Luck!