Re: Best CI for process

Sandy, speaking aobut Tri-X, how long is the toe in your tests? (in D log
values). What EI do you use with it?

Sincerely,

Agustin Barrutia
Bs As, Argentina.
----- Original Message -----
From: "Sandy King" <sanking@clemson.edu>
To: <alt-photo-process-l@sask.usask.ca>
Sent: Saturday, October 01, 2005 1:19 PM
Subject: RE: Best CI for process

>
> Eric,
>
> As noted, my comments were predicated on the assumption that we were
> talking about in-camera negatives and since density ranges of log 3.0
> were mentioned I thought it important to point out that you can't get
> there from here, i.e. no modern general purpose film will allow
> development to a CI of 1.45 and over.
>
> If the subject is enlarged digital negatives or negatives enlarged on
> high contrast continuos tone film DRs of this high are clearly
> possible. I could, for exmaple, get a maximum DR of about 3.4 with my
> Epson 2200 printing with black ink. At this point the question
> becomes, is there any advantage to setting your process so that it
> needs a negative with a DR of 3.0 instead of 2.0? I won't say
> categorically that there is not but I will say that I have never seen
> any visual proof of it. My experience is that so long as you have
> adequate shadow detail you can set the process exposure scale pretty
> much where you want it.
>
> As for the placement of shadow detail at .30 to .45, I have no
> problem with that at all, *for some films". When working with a film
> like TRI-X, which has a very long toe and a constant upward flare in
> the shoulder, overexposing to get shadow detail out of the toe and
> into the straight line (if we may call it that) part of the curve is
> a very good thing because it increases separation in both the shadows
> and in the highlights. On the other hand, if you overexpose with HP5+
> you will increase separation in the shadows, but shoulder compression
> will result in less separation in the highlights.
>
> Sandy
>
>
> >Sandy, Most of my work is in doing enlarged negatives and while the
> >discussion did start out to be about in camera negative development and
> >placement of shadow density, it did get into the density range issue. My
> >large format camera is 4x5, so most of my negatives reach their final
> >expression through the enlarged negative process.
> >
> >
> >Since Kodak's 4125 has bit the dust as did 4127, I have been looking for
a
> >film that was so complete for both darkroom and some in camera work. Some
> >have come close, but most pail in comparison due to the lack of range.
> >
> >In print making, there is no law that says, it must all be done in one
> >solution. Expanding the capabilities of the film by use of toning,
> >bleaching, etc, are fair game. The key is adequate exposure to get your
> >detail off the non responsive area within the toe. To that end, I find
that
> >.3 to .45 above is a good place to start placing your detail.
> >
> >
> >Many early computer generated negatives that were sent to me for
printing,
> >severely lacked shadow separation and were buggers to print.
> >
> >
> >Eric Neilsen Photography
> >4101 Commerce Street, Suite 9
> >Dallas, TX 75226
> >214-827-8301
> >http://ericneilsenphotography.com
> >
> >
> >> -----Original Message-----
> >> From: Sandy King [mailto:sanking@clemson.edu]
> >> Sent: Saturday, October 01, 2005 9:12 AM
> >> To: alt-photo-process-l@sask.usask.ca
> >> Subject: Re: Best CI for process
> >>
> >>
> >>
> >> 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. In other words, you may develop longer and push the
> >> highlight
> >> density to log 4.0 or above, but any density over that reached
> >> at the
> >> point of maximum CI is just garbage density. You might as well
> >> take a
> >> piece of opaque plastic and insert it between the light source
> >> and
> >> the sensitized paper.
> >>
> >> Choice of developer, whether staining or not, is basically
> >> irrelevant
> >> as a factor with regard to the maximum potential CI of a film
> >> since
> >> this is quality is pretty much built into the film. Of course,
> >> if you
> > > use a very energetic formula you will reach the maximum CI
> >> sooner in
> >> development, but it is not possible to push the envelope.
> >>
> >> Since this discussion emerged from a discussion on developing
> >> for
> >> shadow density with in camera negatives I assume that the
> >> subject
> >> continues to be this type of negative, as opposed to enlarged
> >> digital
> >> negatives or negatives enlarged on lith film. In those cases it
> >> may
> >> be possible to reach a CI of 1.45 or higher.
> >>
> >> However, assuming that the subject is in camera film, and sheet
> >> film
> >> also since we are talking about contact printing in palladium
> >> or
> >> platinum, the question remains, which modern films are capable
> >> of
> >> being developed to a CI of 1.45?
> >>
> >> Sandy
> >>
> >>
> >> Etienne wrote:
> >>
> >> >Sandy wrote:
> >> >
> >> >> So let me ask again. What
> >> film/developer/agitation/temperature
> >> >> combination should one use for N development of in- camera
> >> negatives
> >> >> when the density range required for scenes of normal
> >> contrast is log
> >> >> 3.0 or above?
> >> >>
> >> >> And what should one do when the scene requires N+
> >> development?
> >> >>
> >> >> My best estimate for most common films is that you can't
> >> get there from
> >> >>here.
> >> >
> >> >I don't understand the question. The DR of the negative that
> >> just "fits" a
> >> >given printing process doesn't change with the scene contrast
> >> -- it is a
> >> >matter of (1) FB+F plus the image density necessary to get up
> >> off the toe,
> >> >and (2) the Dmax of the film at the shoulder. Neglecting the
> >> small rise in
> >> >FB+F that accompanies longer development, one just develops
> >> until the
> >> >highlight densities are log D 3.3 or whatever.
> >> >
> >> >Note that users of staining developers may find that the
> >> increase in FB+F
> >> >is NOT negligible. (Ditto constant-agitation developing, but
> >> to a lesser
> >> >degree.) M-Q or P-Q developers, or even the non-staining pyro
> >> formulae,
> >> >used with intermittent agitation, do not have this problem. I
> >> develop in
> >> >glycin, which is perhaps the least fog-prone developing agent
> >> known, and
> >> >have never had any problem, even using constant agitation for
> >> 30+ minutes
> >> >at 75 degrees F. [Side note: beware of any glycin you receive
> >> that is
> >> >darker than a sheet of Crane's Ecru paper -- although many
> >> internet sources
> >> >say it works fine, IME it does not. It should be just barely
> >> off-white.
> >> >I'm speaking from extensive experience here -- I suspect I've
> >> mixed more
> >> >glycin developer since commercial glycin developers have been
> >> off the
> >> >market than the next 10 glycin users combined.]
> >> >
> >> >If one's film and/or developer will not produce the required
> >> highlight
> >> >density (or will not produce it without excessive FB+F), there
> >> is still
> >> >hope. Super-proportional intensification (if the shadows are
> >> already at
> >> >the correct density and the highlights are insufficiently
> >> dense) or
> >> >super-proportional reduction (if you expose more to get the
> >> highlight
> >> >densities up where they belong and the shadow densities are
> >> too high), or
> >> >both, can expand DR by log D 1.0 or so. I have even made HP5+
> >> negatives
> >> >with a DR of 3.0 this way, although I don't care for the film
> >> and stopped
> >> >testing.
> >> >
> >> >Best regards,
> >> >
> >> >etienne
Received on Sat Oct 1 11:00:23 2005