Re: filmscanners: RE: filmscanners: RE: filmscanners: Pixels per inch vs DPI

[Arthur Entlich <artistic@ampsc.com>]

Austin Franklin wrote:

  >>Very simply, grain, or dye clouds are predetermined in their location
  >>and shape and are not relocated by picture content.
  >>
  >
  > What about development?
  >


I could just answer this with an "Austinism" and say "what about it?",
but I'll afford you a little more respect than you hand out.

Development obviously is where dye clouds are created from the photon
activated silver grains.  Depending if the film is a positive or
negative type, those grains activated by photons either are used to
create dye clouds or to be areas where dye clouds are ultimately removed
via a bleaching process in creating the final processed film.

Also, some developing techniques can somewhat alter the shape or size of
the dye clouds, as the grain edges can be "eaten away" or softened by
some developers or the dye cloud could be enlarged during the chemical
reaction which creates it, and development could also theoretically
alter what level of grain "activation" will develop into dye clouds by
change of chemical concentration, temperature of the baths and timing.
However, most of this type of thing is done in custom film development
of black and white film, because the need to control so many other
variables within color film development doesn't allow for much playing
around.  Most color film processing is fairly uniform in its method,
assuming it is being done correctly (unfortunately, it often isn't
controlled as well as it should be, which is evident by the number of
people dealing with poor color processing).   This is why almost all
color film is souped in one of two basic color chemistry types (C-41 or
E-6).

It is true that some of the above mentioned grain alterations also occur
during pushing of color films, but usually the intent of these processes
is to extend film sensitivity more than to increase grain, for instance.

Some photographers do pull some color films, which creates an apparent
slower film and might reduce grain size in some cases.

However, I know of no color development technique that is capable of
moving film grain or dye clouds within the emulsion so that they can
line up the grain as a result of the image content. If you do, I'd like
to here about it.


Art

Austin Franklin wrote:

 >>Very simply, grain, or dye clouds are predetermined in their location
 >>and shape and are not relocated by picture content.
 >>
 >
 > What about development?
 >
 > .
 >
 >