Ok... I thought I had seen it all, but this one is new: I am doing some testing for my RH Designs Zonemaster. I need a blank, processed negative. Sounds pretty easy: I take a blank 4x5 sheet from a loaded holder, drop it into a BTZS tube and process like I normally do in my JOBO. ( Prewash 5 minutes in plain water: TMX-RS 1:4 at 75F water bath for 4'30": plain water stop: fix in fresh rapid fixer for 5 minutes: then wash for a while.... Constant rotation of the tube in the water bath)

Inspection of the negative shows an un exposed negative, lightly colored electric blue streak down the middle ( the long way ) of the negative, about 1 inch wide, irregular in shape, but basically really pretty blue and pretty continuous. This looks different in color than the purple color of unfixed/ insufficiently fixed film.

I do not ususally process in tubes, so I am not familiar with the peculiarities. Since the mark is in the middle, it could have some from some form of "touching" from the tube, not allowing the fixer to set the back of the film. So I try again, but this time I fix for 2 minutes in the tube, then 5 minutes more in a tray. Same result, slightly different in dshaope but basically in the same place on the negative.

The tubes are used, but new to me.

Has anyone had similar results? Does anyone have a theory? Something I can try to remedy this?

I am going to put he negative in fixer again, let it sit for a while ( 10 more minutes) to see if there is any change.....


Thanks
Frank