View Full Version : Odd film quality failure

David de Gruyl
18-Jan-2011, 07:03
I had two issues this weekend with one batch of Tri-X. Or at least I think it was Tri-X (320TXP 4x5, current emulsion).

Four sheets of film, two had only the square notch cut out and appeared very faint. A different two had only the pair of V cuts and were completely black when developed (in other words: overexposed). All film, as well as what appeared to be normal Tri-X were developed / exposed at EI 160 and the normal stuff worked beautifully. It is possible that I have the square vs Vs mixed up, but they definitely matched results (squares were consistent with each other, as were Vs).

My understanding of sheet film productions was that the emulsion is laid down before the film is cut, and the cut film is then notched before packaging. Is the emulsion, instead, laid down on the individual cut film? and the notches applied afterward?

I am wondering if this is is a QC failure at kodak or if something else is going on. I do not use any other films that match these notch codes (which was my first thought).

18-Jan-2011, 07:36
My first thought would be to double-check my equipment and procedures before looking at the film. While Kodak QC is pretty good, accidents do happen.
Run another few sheets through and see what happens, then you'll have a better idea.

David de Gruyl
18-Jan-2011, 07:44
I can't. You see, I only had those four sheets that had different notches. All the other film (perfectly normal TXP) works great. Equipment works fantastic. I get consistent results. I even got great results with the TXP that was in the tank with these other four sheets of film.

I could only come up with two possible issues: first, the film was something else (I do use other films, and I might have mixed them up). I don't, however, use anything else with those notches.

Second: the film was supposed to be tri-x, but was somehow screwed up. Note that the notches did not say "this is tri-x", but instead said "this is half the notches that belong on tri-x".

Even if the film was a different film (TXP, FP4+, Astia or E100G are the only 4x5 films I use), it should have had matching notches to one of those, right?