Jack, First I want to correct myself: I meant Kodak RG25 not 50 (I don't even know if there was such a beast as RG50). Second I am not aware there may be different RMS measurements or interpretations for negative and slide film. According to Agfa technical documents they use the same technique for both negative and slide. Maybe you are referring to PGI (Print Grain Index) Kodak introduced to scale emulsion grain to printed paper grain? They do claim that negative film grain cannot be directly compared to positive film and a translation is in order (via a reference printing system / reference paper). Whether this supports a real fact or Kodak just wanted to avoid a direct comparison to its green rival is anybody's choice... Servus, Alin
Jack wrote: JD> Alin, JD> Useful and much appreciated information. Thanks! JD> Pos and neg RMS factors relate to two different JD> scales. The actual conversion factor escapes me at the JD> moment. If I should locate it, I'll put up on list. JD> This isn't to say that the total of all other JD> information you furnished isn't exactly right. Just JD> wanted to make the minor point.
