Archived posting to the Leica Users Group, 2001/08/05
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]> Austin asks: > > > Are there any actual published tests that show > > this "superior" shadow detail? > > The extended response in low light is quite obvious from the > characteristic > curves in publication F-9. The problem with stuff like this is you actually need to understand what it is you are looking at, and what it really means. If you don't have that understanding, you can draw erroneous conclusions from misinterpreting the data. That information does not show that TXP has "superior" shadow detail to TX. What it shows, is under those SPECIFIC conditions, the relative DMin for TX was slightly lower than for TXP. Basically, that TXP has a lower optical density for it's film base than TX does. The curve, and the DRange of any film is highly dependant on image, exposure and development. You will note they were both developed in two different developers. I measured the film base of TXP-120 at 0.15 and the film base of TX-120 at 0.14. Both film was developed in D-76 1:1 at 75F in a Jobo ATL-1500. TXP at 11 minutes, TX at 9. I took the measurements with an X-Rite 810 optical density meter. My readings show that TX has a lower DMin, and therefore "superior" shadow detail (which that concept is actually an incorrect premise, but that's a different issue). This is contrary to your analysis of the Kodak information, which I contend, is erroneous.