Traditionally, slow films showed greater
contrast than did faster emulsions. This was acutely so in color
material. Slow black-and-white film, although more contrasty than
faster films, did not present as many problems because contrast could
be controlled or altered in either processing or printing. For those
who preferred to work in color, controls were just not available,
especially if the film they chose was slow. Until very recently,
contrast control of color material has been strictly limited; for the
non-darkroom worker, nonexistent.
After a while, film-makers tried to make things different, having begun
to offer emulsions that are custom-designed with a nontraditional mix
of characteristics. No longer do slow color films need to be more
contrasty than their faster siblings. Although an ultra high speed
ISO-1600 color film is still not the same with the contrast qualities
of an ISO-100 emulsion, the gap has been narrowed considerably.
Fortunately, we are no longer saddled with high-speed color film that
betrays its user by delivering tell-tale, muddy black-brown shadows and
detail-less highlights. The old axiom of "faster film, less shadow
detail" is far less true today, as it is harder and harder to tell
ISO-100 negatives or slides from ones generated from ISO-400 material.