Geoffrey S. Mendelson wrote:
pico wrote:
Adam wrote:

What does "professional" mean on B/W film? I know what it means on
color film, regarding the color shift.
For Kodak B&W films it means a film base that can be retouched.

It also means different exposure/development. For example I have no idea
if Tri-X and Tri-X Pan Proffessional are different emulsions, but
but the exposure (ISO 400 vs 320 for proffessional) is different.

The difference in development may just be compensation for the greater
exposure.

Geoff.


Tri-X 400 and Tri-X Professional 320 are completely
different emulsions with different tone rendition. The
ISO-400 film is a general purpose, medium toe, film. The
ISO-320 version is a very long toe film intended for
obtaining brilliant highlights in commercial work. It is
useful for some types of portraits. The difference is not
large but quite noticeable if a direct comparison is done.
At one time Kodak made a number of films with the long
toe type characteristic, for instance, many of its portrait
films had this sort of curve.