Stephen, this type of panel test was used for years by Kodak for evaluating prints. My graph was derived from Mees, Revised Edition, page 878, written specifically by J. L. Tupper, in a chapter contributed by L. A. Jones. These works were all contributions from members of the KRL staff. IDK what Jones did at the time you cite, but he was part of the "Mees Team" at the time Mees wrote his book.
Originally Posted by Stephen Benskin
Some excellent treatment of this subject, with examples, is shown in Practical Sensitometry by Wakefield. Example curves and prints are shown from a number of different combinations. Ctein has some very nice examples using modern materials in his book "Post Exposure". I suggest that the contributors to this thread put some of these books on their reading list.
Sounds like you are referring to the 2nd edition of Theory of the Photographic Process. If I remember correctly, the first edition was little more than a compilation of recently published papers. I don't remember the 2nd edition. The 3rd edition has it on page 441 by Tupper, in a section where he is summarizing Jones' first excellent print test. Looking at the curve you uploaded more closely, "Negative Material B" is found on page 502 of the paper in the Journal of the Franklin Institute at the bottom half of the page. The same "Negative Material B" was used again on page 94 of Jones and Nelson's 1940 paper "A Study of Various Sensitometric Criteria of Negative Film Speeds." Personally, I like to go to the source material. It avoids some other authors interpretation of the materials.
Originally Posted by Photo Engineer
I'm sure you used derivative curves all the time at Kodak. I'm just pointing out the origins of this particular one and it was from Jones' work. I have to get a life.
In H&D's original work, you will find an idealized negative curve which has turned out to be the seminal curve for all idealized curves published. Why? Because it is essentially right and is the foundation of all derivative work. Thus, that set of curves can be found (or derived) from very simple work with neg pos materials.
Mine comes from Mees, Revised Edition. Those articles, contributed by many people at KRL, were published in 2 forms. Or should I say 3 for more accuracy. One, the publications you cite were published internally in a second form with some "classified" content. In the third version, they were massaged and republished in one of the varying editions of Mees work. However, long after these, that work continued to be published internally. As time went on, this work delved more into color.
On that topic, I reiterate the fact that W. T. Hanson published the 4 part chart you have used, but he related it to the silver criterion (and the unit neutral) of dyes which often distorted each of the 3 color curves considerably. Thus, to get good curve shape we had to either tweak the spectral sensitization, tweak the image dye, or bend the curve shape of one or more layer in order to get a neutral print in a neg-pos color system.
Hanson has given some of that in his book (Evans, Hanson and Brewer) and it is presented in several other works. I have a copy of his original report.
Did H&D title all their graphs as "Negative Material B" and have labels "first excellent prints" and "just acceptable prints"? No. All I'm doing is pointing out the reference material. My god, give it a break.
I was referring to the fact that the curve "Negative Material B" was an archetype used by everyone and basically started with H&D. It is a long straight line with a slope of about 0.6 - 0.7. Thats all.
Originally Posted by Stephen Benskin
Not photos but see if this helps.
Originally Posted by MattKing
Remember these are not to scale.
Without a shoulder the separation on the negative is greater but it falls outside the print range, that detail is lost unless you burn them back in.
With shouldering and placement high on the curve the negative should straight print with better highlight detail.
Time to print out some graphs and text
The whole idea of processing is to produce a target negative density range for various subject luminance ranges. If the NDR and print LER match, there is a good likelihood of a quality print. If the highlight exposure falls on the shouldering portion of the curve, the highlight detail will be compressed further than what normally occurs from enlarger flare and the need for high mid-tone contrast.
Originally Posted by markbarendt
Mark, you've mentioned the negative shoulder a couple of times in this thread. I'm thinking you have some concept in mind.
Matt, you know what too dark, too light, flat, and contrasty look like. Just apply it to the reproduction curve. Imagine a normal looking picture for the preferred reproduction curve. For any other shape of the curve apply one or more of the four possible choices.
I actually do have an idea or two that I'm toying with.
For one, when living with prints for a bit and viewing them from across the room in normal life over a week or two I'm finding that I like them brighter. My darker prints while very enjoyable at close range and bright lighting are tougher to enjoy from across the room. I find that same truth, for me, when out in restaurants and other places when viewing the work of others.
In my printing the mid-tones are creeping up brighter and pushing some of the highlight detail off the scale on the print. To put this in real terms of subject matter. The whites of a subjects eyes are competing with the bright side of the nose and forehead for room on the paper curve.
I've been playing with trying retain a bit more detail at the very top, even if its compressed a bit, while retaining good mid-tone snap. I'm trying to find the sweet spot here and see if for example FP4+'s curve fits my needs better than say TMax's or delta's.
The intent is to make printing easier with less burn and dodge.
In essence the question I'm asking is "can I use the inherent compression a shoulder imparts to my advantage here?"
I'm not sure I'm following. I guess it depends on the relative subject brightness of the whites of the eyes and hot spots on the nose/forehead. If they are very close, they will end up on the same part of the film curve. If they are further apart I suppose you could expose/develop to push only the brightest highlights onto the shoulder.
To me this still sounds more like it falls under print controls (ie selectively darkening certain highlights relative to other highlights even though they may have similar densities in the negative).
But I guess what's confusing me a little is when you're talking about using the shoulder but also saying you want to retain more detail at the very top. That's why it ends up sounding more like a printing control issue than a negative issue.
Regarding the specific films, the three you mention are nearly the same until you get to the extreme highlight densities. TMX 100 for example, tends to shoulder a little more gradually (ie it starts a little earlier) than Delta 100.