The DARKROOM COOKBOOK, Third Edition

Film Development 35
● Conventional-grain emulsions use grain which is either fl at or a hybrid of cubic and fl at grain.
To varying degrees all of the fi lms in this category utilize color dye sensitization in order to
replace some of the silver in the emulsion and increase the fi lm's sensitivity to light. Among
others these fi lms include Efke 400®; 1 Neopan® 400 and 1600; Ilford Pan F®, FP4�®, and
HP5�®, and Kodak Plus-X® and Tri-X®. These fi lms respond somewhat to changes in developer
formulae but not as much as old-style emulsions. They have more hardener in the emulsion and
are not as easily damaged when wet. With reasonable care in handling, it is not necessary to add
additional hardener to the fi xer. 2
Elsewhere in the Cookbook these will be referred to as conventional-grain emulsions.
● Modern fl at-grain emulsions use fl at grains of silver which have almost no depth. Instead of
appearing like grains of salt or pebbles, these fl at grains appear more like microscopic fl agstones.
Flat-grain emulsions rely heavily on color-dye sensitization to further minimize the use of silver.
The least amount of silver and the fl attest grains are found in Kodak T-Max® fi lms. These emulsions
are the least responsive to Zone System contraction and expansion and changes in developer
(see: And in This Corner: Tri-X vs. T-Max).
Typical of these are Ilford Delta® 100, 400, and 3200; Fuji Acros® 100; Kodak T-Max® 100, 400,
and P3200.
Elsewhere in the Cookbook, these will be referred to as fl at-grain emulsions.
FILM TYPES
Grain and graininess can be emphasized or reduced by the choice of enlarger
light source (cold light and diffusion light sources suppress grain; condenser and
less commonly found point-light sources emphasize grain).
● Resolving Power: The ability of the emulsion to record fi ne detail. Resolving power
is determined by photographing a line graph. Although the quality of the lens does
affect the resolving power of the fi lm, most lenses made today have higher resolving
power than the fi lm is able to reproduce. Both fi neness of grain size and graininess
affect the smoothness of tone and the resolving power of the fi lm.
In addition to different types of emulsions, there are different types of fi lm. These include
panchromatic fi lms, which are sensitive to all colors of visible light to varying degrees (these
include all those fi lms mentioned in the previous section); orthochromatic fi lms, which are
primarily blue-sensitive; infrared fi lms, which record in the infrared or near-infrared spectrum;
document fi lms, which are extremely high in contrast exhibiting little or no mid-tones unless
1 Efke 400 is the discontinued Agfa APX 400 and is a conventional-grain emulsion, not an old-style emulsion
as are the other three Efke fi lms. There is some speculation that it will soon be available under the
Adox label as ADX 400.
2 Hardener protects the fi lm while it is wet and vulnerable. It serves no purpose for a dry emulsion.