From: Sandy King (sanking@clemson.edu)
Date: 09/22/02-11:50:31 AM Z
Jeff,
Comments to your disadvantages.
>Sandy: Disadvantages:
> (1) Toxicity. I believe I have this well under control in my work
>environment, but I don't think it can be discounted completely. And
>I do have a cigar pretty much every evening (for crying out loud).
This is mostly a crock. Mix your solutions in a well-ventilated area
and use gloves if you tray process and so much for that. Most other
reducers are also toxic to varying degrees, and everyone should use
gloves anyway.
> (2) The difficulty of determining the density range of pyro
>negatives. I don't want to spend hundreds on a densitometer and,
>even if I did, I've heard a range of opinions on the point of doing
>so (I guess the blue channel of a Mantis is supposed to be pretty
>good ...). Still, it would be really nice to be able to use the
>simple/elegant method described by Weese & Sullivan (two cards with
>holes -- one goes over the negative, the other goes over a Stouffer
>strip, etc.), but this ain't going to work with a pyro stained
>negative.
The simple method described by Sullivan and Weese works just
effectively with a pyro stained step wedge as with a traditional one.
And since you need to do your own film testing anyway it really makes
no difference in end for this method whether you used a stained or
traditional negative.
Now, if you are really into sensitometry and using a densitometer, as
is Dick Arentz, (and me also for that matter) the stained negative
does present some problems in reading, and this will vary according
to the printing process and exposing light source. It is not good
enough to just read through the blue channel by itself to get an
effective DR. But if you really calibrate all your real negatives
with your real printing process and procedures (as you know you
should anyway), a reading of your negative through the blue channel
will accurately reflect printing density.
> (3) Long exposure times printing w/ pt/pd due to the UV-blocking
>pyro stain. I believe this sacrifices smoothness in the image.
>Now, I've covered this to a large extent by changing to a powerful
>metal halide light printer (1000W, 5200K). I haven't seen a
>printing time over 13-14 minutes, which would be a VERY much longer
>printing time under black lights (for instance).
Exposing times are primarily determined by shadow density, which with
a pyro stained negative shows the least proportionate stain. The
difference in actual reading between my traditional negative and pyro
stained negatives from log 0.15 to log 0.45 is almost always less
than log 0.07, which is less than 1/2 stop of additional printing
speed.
Most of the increased proportionate stain is in the highlights, which
as you know must be controlled by the contrast control procedures of
the process, not by printing time.
> Also, I've learned to minimize general stain. Still, I get quite
>puzzled sometimes. On the one hand, a guy is comparing my pyro neg
>to his and saying, "See how yours has so much more dang image
>stain?!" Well, I thought getting strong image stain was the whole
>point of the stuff.
No, no, and a thousand times no. Increase general stain is just
garbage that leads to increased exposure times since it is in the
shadows as well as the highlights. What you want is proportionate
stain, very little in the shadows, increasing slightly in the
mid-tones, and greatest in the hightlights.
>This is connected to another phenomenon: As I apply plus, plus-2
>and/or plus-3 development with WD2D or PMK on FP4+, I get the
>desired density in the highlight areas (quite predictably) but I
>also get more and more aggressive image stain. -jb
I suspect that you are not adjusting for effective negative speed
when exposing in N+ situations. As you increase time of development
effective negative speed also increases, and quite significantly.
Depending on film an increase of up to 2X or 3X the effective speed
of the film is not uncommon. And FP4+ is one of the films that
responds most in terms of a speed increase with increased development
times. If you don't compensate for this the result will be greatly
increased density in the shadows, which you don't want since you 1)
don't need it, and 2) it can cause a huge increase in printing time.
Sandy King
>
>At 10:31 AM 9/22/2002 -0400, Sandy King wrote:
>>Jeff Buckels wrote:
>>
>>>I tried something like this inquiry a month or so ago and got no
>>>response. Perhaps on this occasion some of the more indulgent
>>>members of the list are checking their email:
>>>
>>>Let's say that I don't give a flying flip (note the
>>>carefully-crafted euphemisms, Gordon) how my negatives would work
>>>for silver printing (hence, I don't care whether my negatives will
>>>work both for silver and pt/pd)..... In that case, what is the
>>>justification for bothering with pyro? Assume as well that I
>>>reject the Great Separation in the High Values justification (Dick
>>>Arentz seems to reject it; surely I know no better than he) and
>>>that, while I appreciate the economy of pyro, I doubt that the
>>>economy alone offsets the disadvantages of pyro. So, there then
>>>-- Why use pyro?
>>>
>>>Jeff Buckels
>>
>>I resisted comment the first time around on your inquiry because
>>threads on pyro tend to become something of a quagmire. Some
>>attribute almost magical qualities to pyro developers while others
>>are perfectly satisfied with the results they get with the
>>traditional developers they have used since they first started
>>doing photography and apparently see no need to change. Nothing,
>>and I repeat *nothing* we say here is going to change any of that
>>for these people. However, I am curious as to what you see as the
>>disadvantages of pyro? As someone who uses both traditional and
>>pyro developers I have some thoughts of my own on this, but wanted
>>to first see what you, or others, perceive as real disadvantages
>>with pyro.
>>
>>
>>Sandy King
>>
>>
>>
>>
>>--
--
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