From: Stane Kočar (firstname.lastname@example.org)
Date: 04/09/03-03:09:14 AM Z
Tom, I tried to look on your web site, but the pictures are missing (in my
Microsoft Internet Explorer).
What about others?
Stane Kocar, Slovenia
----- Original Message -----
From: Tom Ferguson <email@example.com>
Sent: Wednesday, April 09, 2003 2:33 AM
Subject: Re: Film Speed and Negative Development
> Scott, something is odd! In "general" using the 0.1 over FB+F (fine for
> silver gelatin, not so good for many/most alt processes) you will get
> "about 1/2" the company rated value (FP4 rated at 125, personal EI 64 or
> 80). Different developers don't change it that much :-(
> For you to be getting "3 to 4" stops lower (EI 16 to 8) indicated bad
> developer,bad testing technique, bad meter, or bad film.
> For alternative process work a good "general" rule is to decrease your
> "silver/0.1/Adams" EI test by 2/3 stops. If your FP4 manufacturer is ISO
> 125, "silver/0.1/Adams" test is EI 64, use EI 40 for alt. That is very
> "general". I have an article you can read about film testing for alt
> processes at:
> But again, for you to be getting " 3 to 4 stops" (as opposed to my
> "estimated" 1-2/3 stops) is odd enough that I "assume" something is
> "broken or bad".
> On Tuesday, April 8, 2003, at 04:36 PM, Scott Wainer wrote:
> > Greg,
> > I can almost live with whatever film speed I get. I thought that it
> > might be
> > about 1/2 - 1 stop less, I just didn't expect it to be 3-4 stops less
> > than
> > what the manufacturer rated it at. If that is truly the case then I will
> > just go back to shooting Pan F+ (ASA/ISO 50) which gives me an EI of 32
> > with
> > the same setup, chemistry, and processing.
> > What I don't get is that all of the published data shows a higher EI
> > than
> > what I am getting; some times higher than what the manufacturer rated
> > it at.
> > Could my setup be that far off that I am loosing 3-4 stops?
> > Scott
> > firstname.lastname@example.org
> > ----- Original Message -----
> > From: "Greg Schmitz" <email@example.com>
> > To: <firstname.lastname@example.org>
> > Sent: Tuesday, April 08, 2003 7:13 PM
> > Subject: Re: Film Speed and Negative Development
> >> Scott:
> >> I don't want to rain on your parade, but it has been my experience
> >> that it is almost impossible to raise the true speed of any film - no
> >> matter what. I have exposed and developed hundreds, perhaps thousands
> >> of rolls of test film. In reality what is usually meant by an
> >> "increase in speed" is really an increase in contrast. The point at
> >> which the films curve begins to pivot upward does not change, it just
> >> gets steeper. I have seen minimal increases in true film speed with a
> >> few special additives, pre/post-exposure, and exposing film to certain
> >> gas fumes.
> >> Depending on what your criteria are for your negative you may well
> >> find that your final results are lower than that stated by the
> >> manufacturer. I base my film tests directly on the requirements I
> >> have for a given type of positive and frequently rate the films' speed
> >> differently for the process that I am using to produce the final
> >> positive. My standard exposure for Tri-X 135, for example, is usually
> >> either 200 or 320.
> >> -greg schmitz <email@example.com>
> Tom Ferguson
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