Yes. People do this. For example, push-processing E-6
film means extending the time in the first developer.

There are lots of other possibilities. Just depends
on how much time you want to spend tracking them down.
And how much you want to spend on film.

Laura Halliday VE7LDH     "Que les nuages soient notre
Grid: CN89mg                    pied a terre..."
ICBM: 49 16.05 N 122 56.92 W       - Hospital/Shafte

E6 (color slides) is always processed to produce a certain
contrast range and to be within specific measurable parameters
(AIM values.) Labs do not shorten processing times to save
time or money, short cutting image quality. Developing times
are rather adjusted to meet AIM values. Commercially the E6
process is standardized to produce optimal results for viewing
color transparencies via projection. However, there are good
labs and bad labs, good technicians and bad technicians. A
commercial E6 process is either in control (determined through
plotting control strip density readings) or not. You simply
need to find a reputable lab (reputable based on the number
of professionals who are satisfied with that lab.)

You can altering color processing and obtain any results you
want, but you will not improve on E6 quality since you will be
altering the color, speed, and maximum densities beyond those
for optimal color transparencies. Altering E6 process controls
is mainly done for push or pull processing of over or under
exposures, whether accidentally or deliberately. This will
alter the contrast, but the overall image quality (shadow and
highlight densities and color) will degrade depending on the
degree to which you push/pull the film.

Sam, B&W processing is not standardixzed, reutling in many film/developer
combinatins. Since you are basically dealing with only one emulsion rather
than the three (red, green, and blue sensitive) in color films, it is easy
to coreect for contrast variations wihch would results hwne a different
developer is selected to offer finer grain or more shadow detail.

Color processes are designed to specific parameters and the films are then
designed to produce the best quality when processed at that standard.
Manufacturers of color film and paper processing equipment usually design
their machines to meet the process specifications as spelled out in the
Kodak Z-manuals. Some have been known to cut corners to save a few bucks,
but the best film processors made by companies such as Refrema do not.

The processing labs don't have the option to reduce one of the chemical or
wash times since these are built into the processor. They could cut back on
water flow or use colder water rather than at specified settings to save a
little, or they might not take good steps to assure their process is running
in control.

Any modifications to something like the first developer in E-6 to try and
obtain finer grain could have drastic effects on your color by not providing
the same contrast or rate of development in all three emulsion layers. That
is why the good labs take great effort in ensuring their process is on aim.

I don't use E-6, only C-41.

Varying the time/temp can cause color shifts. Kodak publication Z-131,
"Using Kodak Flexicolor Chemicals", contains a series of charts showing what
happens when you vary time, temp, agitation, chemical mix, phase of moon,
type of underwear (boxers or briefs), etc. Kodak recommends processing a
control strip (a precisely exposed piece of film which, depending on
size/format, contains a yellow step, a D-max step, a D-min step, and 10
equal increment density steps) daily or more often. The densities of the
colors are measured and plotted on a graph. Over a period of time, the graph
plots may very. These variations are compared to graphs in the book to
attempt to determine what the problem is, and what to do to correct it. For
example, if developer time is increased from 3:15 to 3:30, all the graph
plots will rise fairly evenly. If the time is increased to 3:45, the rise
starts to separate between the three colors: Dmax-Y red continues up, but
blue levels or falls slightly. All this can cause color balance problems.

Ken Hart