Kodak Plus-X and Tr-X Films are not t-grain films

[laser]

I have read several postings saying that PX and TX are partially t-grain films.

I lead the teams that commercialized T-max Films and then many years later (for old times sake) I did the same moving PX and TX to Kodak's most advanced coating facility in Building 38. PX and TX do not have "t-grain" emulsions. For TMY and TX the difference is clearly demonstrated in Figures 1 and 3 of "Making KODAK Film". Both of the films shown were made in B38. I am grateful that many APUG readers have the book.


Prints from different films do have different appearing grain structure because the films are very different. T-grain films have greater covering power than 3D grain films. Another important but usually ignored characteristic of t-grains is they provide greater surface area for dyes to be attached. These sensitizing dyes influence the spectral sensitivity and increase the light sensitivity allowing the grains to be smaller. During fixing of the unexposed AgX is dissolved releasing the sensitizing dye so the pink cast frequently seen in T-Max Films is eliminated.




Robert Shanebrook
MakingKODAKFilm@yahoo.com

 

[Gerald C Koch]

To clarify things, if you are referring to my post I qualified my statement by saying that the new films used some of the T-grain technology. This could be the use of different sensitizing dyes, etc. I never said that these films were T-grain films. Pesky things be these qualifiers.