Film Notes
The Old vs. New Kodak Film Controversy
As I mentioned at the beginning of Chapter 9, there has been a great deal of confusion and some controversy about the extent to which Kodak's films have changed. What is clear is that Kodak's emulsions needed to be modified to accommodate the relocation of the plants they use to apply the emulsions to their film bases (or the "coating alleys" as they are known). Many photographers have discovered that prints made from these new films have more pronounced grain and harsher tonal gradations than the old films and empirical tests have confirmed these results. For reasons that aren't clear, this effect seems more dramatic when the new Kodak films are processed in Kodak D-76, a developer that was once the standard for many photographers. Our tests indicated that these new films have much better speed and contrast characteristics when processed in Kodak XTOL and T-Max developers. This is especially true for Kodak's 100Tmax (T-Max 100) and 400Tmax (T-Max 400) films.
Tabular Grain Films: T-Max and Delta
By applying Tabular Grain or T-Grain technology to black-and-white emulsions, Kodak and Ilford have produced films that have substantially less grain than standard emulsion films. Tabular refers to the much larger and flatter shape of the silver crystals in the emulsions of these films. The greater light absorption qualities of these flat crystals allow the manufacturer to produce a thinner emulsion that results in substantially finer grain.
Kodak's T-Grain films are T-Max P3200, 400TMax, and 100TMax. Ilford's T-Grain films are Delta 100 and Delta 400. The finer grain and excellent image quality of these films will no doubt make them very popular with serious photographers, but my test results indicate that T-Max and Delta have unusual characteristics that should be given special attention.
1. I found 400TMax and 100 and Delta 400 and 100 to be no faster than 400TX (Tri-X) or 125PX (Plus-X), respectively.The advantage of T-Grain films is that they have substantially finer grain. 100TMax has grain as fine as the old Kodak film Panatomic-X, but 100TMax is much faster.
T-Grain films are also extremely unforgiving of underexposure. 400TMax and 100TMax look best when developed in T-Max or T-Max RS developer at 75 degrees, but be sure that you place your Important Shadow Area no lower than Zone III on the scale.
Never use T-Max developer with sheet film. See the information on Kodak T-Max under the section Developer Notes.
2. T-Grain films are extremely sensitive to changes in development time, temperature, dilution, and agitation rate. Inconsistencies in any of these variables will produce noticeable changes in the contrast of your negatives. For this reason,T-Max films are very useful for Expansion and Contraction developments. Make an effort to be as consistent as possible in your development procedures.
3. Because T-Grain films are unusually responsive to changes in development time, the normal Expansion and Contraction formulas don't apply to these films. See the section Expansion and Contraction Development Times at the end of Chapter 8 for details.
4. Kodak indicates that T-Max films require less compensation for the reciprocity effect than do conventional films. Ordinarily when your indicated exposure is 10 seconds, a 50-second exposure is required, with a 20 percent reduction in your development time to avoid underexposure and overdevelopment. With T-Max, Kodak recommends an exposure of only 15 seconds for a 10-second indicated exposure with no reduction of your development time (see Appendix O). Standard reciprocity failure charts apply to Ilford's Delta films.
5. Longer fixing and washing times are required with T-Max films to clear special dyes added to the emulsion. These dyes will turn the fixer red and exhaust it faster than normal. Ilford's "Core-Shell Crystal Technology" allows Delta 400 and 100 to have the advantages of a T-Grain emulsion without the special dyes that cause T-Max films to stain the fixing bath.
Chromogenic Films
This class of films is based on color negative developing processes. These films have characteristics that are substantially different from normal black-and-white materials. Kodak's BW400CN has a T-Grain emulsion for very fine grain and sharpness.
1. Because the image in a chromogenic negative is made up of densities of black-colored dye instead of particles of silver, they are less grainy.
2. Overexposure tends to reduce the appearance of grain because as the density of the negative increases, the microscopic spots of dye merge to form a continuous image. This allows a great range of exposure latitude when working with these films; usually ASAs between 25 and 1600 can be used on the same roll with satisfactory results.
3. Because chromogenic films must be processed to C-41 color standards, you can't alter the development time to compensate for changes in subject contrast.
4. Since chromogenic films are designed to be printed on color papers, you'll need much longer times and higher contrast settings when used on black-and-white papers.
Continue reading here: Contrast Control with Paper Grades
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