From: Sandy King (sanking@clemson.edu)
Date: 09/22/02-01:36:04 PM Z
Jeff wrote:
>Thanks. There's one point here where we didn't communicate, viz.,
>the question of increased stain w/ plus development. I'm not
>talking about general stain; I'm talking about image stain. The
>unexposed film edges remain clear. -jb
Good. Then what you are seeing is not an increase in general stain,
but an increase in overall density caused by too much exposure. You
will see this with other developers as well.
Sandy King
>
>
>At 01:50 PM 9/22/2002 -0400, Sandy King wrote:
>>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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