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).
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).