I've attached two Quality/ Exposure Curves. This is the text that relates to Exposure Quality Curve 1:
"The results are summarized in Fig. 1. The solid curve shows that the quality of the contact prints increases rapidly at first as the camera exposure increases and then reaches a plateau, where it remains constant over a long range of camera exposures. Eventually, the quality decreases. The range of camera exposures over which the print quality remains nearly equal to the maximum quality is defined as the camera-exposure latitude. Each of the intervals marked along the camera-exposure axis is one camera stop. In the case of the solid curve, where the contact prints were made from 4- X 5-in. negatives of a studio portrait scene, using the optimum grade of paper for printing each negative, the camera-exposure latitude was 32 times, or five camera stops. The camera exposure marked a corresponds to a safety factor of 1. The camera exposures marked b and c correspond to safety factors of 2.5 and 4, respectively. There was, obviously, no loss in print quality at either of these two levels of exposure when the prints were made by contact.
In the next part of the test, represented by the dashed line in Fig. 1, the same film, subject, and lens were used as before but the size of the negatives was much smaller as a result of increasing the camera-to-subject distance until the size was typical of the negatives obtained in a 35mm camera. These negatives were enlarged 10 diameters, using the optimum grades of paper, and the enlargements were judged for quality. As shown by the dashed curve, the heavily exposed negatives gave enlargements of lower quality. This loss in quality was due to a very noticeable increase in graininess with increase in negative exposure. At the exposure corresponding to a safety factor of 2.5, the quality was slightly below the maximum quality. The camera-exposure latitude was about 3 times, or approximately one and two-thirds camera stops."
When i last met B B he told me that he theese days was using: Kodak Tech Pan, Fujii Acros, Ilford Delta and FP4. He admitted using Tri-X but addet:
- It isnt the same film as it used to be.
"...I know Barnbaum advocates placing shadows on Zone IV, and also cutting the ASA in half for standard developers. So, he is essentially saying, "for an ASA 400 film, set your meter on ASA 100, and place the shadows on Zone III...." by ParkerSmith
Bruce, a B&W master printer and expert, is saying to cut your film by 50% (ISO 400 to ISO 200) and place important shadow detail on Zone IV. (If you have seen the luminous quality of Bruce's prints, you would understand why he advocates placing important shadow detail on ZIV.)
Ansel stated "... placing shadow detail on Zone IV or higher. (See page 61, paragraph 3, line 6 of the Negative.), will yield a fuller and more luminous detail...." Once you have placed the shadow detail on your desired Zone, you use developing to control your highlights.
You have to do development testing (your film, camera and chemistry) to determine where full detail will be present in the highlights (Zone VII,VIII, or IX) and are printable on your paper of choice.
After saying "put shadow detail on Zone IV", in the next breath he says "and then adjust for it in the darkroom".
He also speaks out against testing your materials.
It works for Bruce, but I would never try it because I lack his knowledge and experience.
It's all a very individual, idiosyncratic, and somewhat iconoclastic masterly approach.
In the week I spent with him, he proudly changed just about every rule that I had ever heard regarding photography. Masters can do that. But if you are less than a master, don't try it.
I have only been going this in earnest since 2004. That said I have learned that rating at half box speed and placing 'important' shadow detail on zone IV gives me the look I am after. As stated, this method requires film development testing and subsequent printing to determine where your highlights need to be.
In short - fully exposed and gently developed negatives make lovely prints and offer lots of choices in the darkroom when printing with multigrade papers.
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If you break it down, Barnbaum isn't doing anything at all out of the ordinary. According to jscott, he's not testing, so he has to be using the film's ISO as a starting point and then setting the EI at 1/2 the ISO speed. How many people already do this whether automatically or through Zone System testing? I've frequently make the point that ZS testing has different testing parameters than the ISO speed testing which will result in EIs that are consistently 1/2 to 1 stop lower than the ISO speed (without taking equipment into account).
Originally Posted by jscott
Next he opens up an extra stop when shooting which is no different than rating the film a stop lower. So, compared to ZS testers, he's only over-exposing one stop. Even considering he's over-exposing the film two stops from the ISO speed, it's no big deal with 4x5 film.
My problem is how he explains it can potentially confuse people. While not a stickler for ZS etiquette, if the intention is to print a tone on Zone III, then you really aren't exposing it on Zone IV, you're exposing it on Zone III on a film that has its EI set differently. Another point I keep trying to make is there isn't a fixed correlation between Zones and negative densities. Over-exposing the film simply moves everything toward the right on the film curve.
Barnbaum's approach is not as radical as it might at first appear.
Last edited by Stephen Benskin; 12-21-2011 at 07:45 AM. Click to view previous post history.
If we are to establish a negative density range by which to develop the negative to, there must be. And so, in the ZS "proper", there is. The usage of the term "proper" is in reference to ZS thinking as it is taught in The Negative, for what that may be worth to anyone. I understand that you may not believe it to be so proper, but I am not one who will generally argue any minor points of theory with what I consider to be obvious success.
Originally Posted by Stephen Benskin
We can only specifically control two points on the curve with each development of the negative. Those two points on the curve require a fixed relationship between a zone and its negative density------the speed point, Zone I, with the ISO rating that yields a density of between .09 and .11 and the Zone VIII negative density calibration point for the "normal" development time. Back in the early 80's when The Negative was written and given the materials at the time, AA decided, quote: "I have found that 1.3 above fb+f is a useful standard for Value VIII, for diffusion type enlargers." He then adds a clarification later by saying, "I have used Value VIII as a standard for high-value density specifically because of its importance as the lightest area in a full-scale image that retains some texture." Now, I don't presume to think that any quotes provided will pursuade anyone, I just add them for clarity of my point.
Those two points on the curve establish the negative density range, as described in the ZS, between Zone I (0.1) and Zone VIII (1.3) (range = 1.2) for any given negative that is to be developed under one of the various development times, generally from N+2 down to N-2 or -3, that has been established through "proper" testing.
The range should not be considered as etched in stone, and in ZS testing the the main questionable variable is the upper density limit. Adams recognized then that, depending on the trend of the exposure scale for the "so called normal papers", with normal implying grade 2, "this optimum range must be subject to continual review and revision as required." The most notable example that I have come across is with Alan Ross, he's supposed to be toying with the idea of calibrating his "normal" development time off a Zone IX negative density of 1.45, extending the density range to 1.35. His reasoning being that with Zone VIII calibration, a -2 development time may not produce densities that will print as paper base white, presumably with today's papers.
Last edited by CPorter; 12-21-2011 at 10:40 AM. Click to view previous post history.
Barnbaum's ability as a photographer and printer can't be denied.
However to try and re-define the ZS based off his own methodology, I think, is wrong. No wander the ZS over the years has been thought to be a madening thing to learn. After setting in that class and having never gone to the original source to learn the ZS, then, to subsequently go to that source, a person would be pulling their hair out.
I agree, what a good way to confuse someone if they thought they were in that class to learn the ZS. Perhaps BB stated, in the beginning, IDK, that his method departs drastically from how AA taught the ZS. That is perfectly fine.
However, if that is not the case, to tell a class that it is "wrong" to place a shadow on Zone III for textural purposes is a drastic departure, and hugely arrogant---- and to suggest that only if you want to develop a "tone" on Zone III is it ok to then make a Zone III placement, again, a drastic departure, and hugely arrogant, IMO. All of that is absolute nonsense---as ZS teaching points.
When I read my words here, it sounds angry, but it's not meant to sound that way.
Last edited by CPorter; 12-21-2011 at 01:03 PM. Click to view previous post history.
What might have one worked traditonally as a "thick neg" technique for Tri-X, might be horrible advice for films with different curve characteristics. And a lot depends on how you print. Modern
VC papers will soemetimes let you have your cake and eat it too. A few people respond to Barnbaum's doctrine well, but I personally find it wacko. The actual shape of the bottom of the
curve is way more important than the alleged Zone per se. With straight-line films I sometimes base
the shadow reading way down on "Zone I" or even "0", but with something like HP5 it would be more
like Zone III. Just way too many variable to make a religion out of any of this. I'm very comfortable
precisely working with a variety of films, but it all takes testing and actual printing.
I have not done a formal test but, based on my 25 year experience with the film, I suspect that enlarged T-max 35mm film does NOT behave that way, and has more of a plateau in the exposure vs quality curve. But this could likely be a muti-page discussion in itself.
Originally Posted by Stephen Benskin