Re: Best CI for process

Etienne,

 From your many posts to this list I know you to be a very smart and
knowledgeable person. So I am truly baffled at your claims that it is
possible to develop most modern films to a CI of 1.45 or more.

Have you actually plotted curves with these films and done the
calculations to figure actual CI, or are you basing your comments
simply on Dmax figures? If you do the former you will see, beyond any
shadow of a doubt that what you claim, i.e. CI of 1.45 and true
density range of 3.0 or more, is an impossible proposition for most
modern films. You may be able to coax that much CI out of a very few
of the modern T-grain emulsion films, such as TMAX and Delta, but you
will never get it from films the films from Eastern Europe, not even
close.

Sandy

> > A negative with a DR of 3.0, let's say one that has a B+F of log .30
>> and a highlight reading of 3.30, must by necessity have a CI of over
>> 1.45. The problem is that there are very few films, if any, that can
>> be developed to a CI of 1.45. Most films are not even capable of a CI
>> of as much as 1.2. Once they reach a CI of 1.2 any further time in
>> the developer simply increases density equally on all parts of the
>> curve, from the shadows to the highlights, but it does not increase
>> CI.
>
>For the most part, I have not found that to be the case. For the last some
>years I have used mostly T-Max 100 and 400. These will give a Dmax of more
>than 3 and a FB+F of 0.35 or less with my glycin developers or, I believe,
>with HC-110 or most any M-Q or P-Q developer. Several Eastern European
>films I tried (house brands from US suppliers) will do it, too, but I lost
>a few too many images to coating defects with these. Plus-X would, the
>last time I used it (two or more formulations ago), give a Dmax of over 2.8
>with FB+F in the 0.4 range, but I never liked its curve much. The only
>commonly-available films I tried that would not do it were Tri-X and most
>Ilford films, even of the previous generation, with HP-5+ being the worst.
>
>Best regards,
>
>etienne
Received on Sat Oct 1 14:15:48 2005