It doesn't look like the barns changed to illustrate the compression of tones in the toe.
But my ground glass has no grid and a fresnel.I should make the barn upside down and reversed with a focusing grid over it
But my ground glass has no grid and a fresnel.
Lee
Let me ask you a question. If you have a scene which is 15 stops of brightness range, do you think you can reproduce all the tones in that scene in a print?
Yes you can, and the print does not have to look ugly. The important point is to capture all tones in the negative. Once that is done, you can represent any of these tones (and all of them if you like) in a print through proper exposure and contrast selection, combined with selective dodging and burning. That's how many of the famous AA prints were done.
... Did you mean they could all be represented...
but not necessarilly each by a unique tone?
Ray
I meant that all 15 stops could all be represented, each by a unique tone.
Let me explain how I get to this statement.
Unlike digital, film and paper are continuos-tone imaging. So, no problem there. Let's now assume that a film can capture an exposure range of 15 stops (it can capture more by the way).
With shortened development (N-3 for example) you get most of it into the normal negative density range. Some of it will be outside of a paper grade 2, but grade 0 can probably render all of it. Unfortunately, that is unlikely to make a nice print (battleship-gray alert).
However, compensating film development, in combination with normal grade paper, and strategic burn-in will be able to render a wide range of exposure and not lose any tones. It will compress some, but not lose them. The trick is to compress the unnecessary and highlight the important.
Attached is a sample of a print rendering tones from Zone I to Zone XI. OK, not quite 15 stops, but the technique is the same. By the way, a 10 stop range is not unusual in nature; a sunlit window in a dark church can provide more of a challenge.
... a lot of people seem to think that because you can get it in the negative it follows that you can get it all on the print. Well no you can't. You can only print part of it which fundamentally changes what you saw. Again that doesn't matter.
Stephen,
The idea that any method is successful when the curve is straight is important. Your six variables are also important. In my practice, my curve is straight. Also in my practice most of these variables are out of my control. For example when backpacking, if I find a scene I want to capture, I have to take the picture at the moment because I am moving on and won't be back, possibly for several years if ever. I'm stuck with whatever time of day or sky conditions are there. If I can talk my buddy into camping near that spot I have a chance for afternoon light and if I am lucky there will be weather.
I still maintain that you can. I am not throwing any tones away; I may stretch or compress them, but they are all there. There is no need to create a negative that allows me to make straight print on grade-2 paper. That only work well for 'normal' subject brightness. I am better off with a negative that has all the detail I want on its straight line portion. I can print all of it with extra exposure or by holding the exposure back in certain areas. Toe and shoulder densities are hard to print. I stay away from those if I can.
There is no need to create a negative that allows me to make straight print on grade-2 paper.
If you use any kind of pull development or compensating development you are throwing away tones(and detail) at that stage and if you use a developer which catches the whole subject in a relatively normal CI all the way up to higher than normal negative density, then you can't print without throwing away tones. .
... I totally understand the Adams-school theory of getting as much information as possible onto the negative for later use, but Adams himself, in his books, says that the Zone system is not designed to make a negative that is easy to print; it's designed to leave as many darkroom options open as possible. ...
There is a misunderstanding of the tone reproduction cycle here.
Reading Adams, one gets the impression that his goal was always to get a negative that could be printed straight on a grade 2 paper. But then further reading reveals that he pretty much never made a straight print on grade 2 paper...
A solar altitude of 40 degree is part of the standard model. The illuminance of the Sun at a normal angle is around 10000 fc. At 40 degrees to the subject it is around 7660 fc. The standard model for exposure uses approximately 7680.
I've attached a print quality vs camera exposure curve for short and long toed films. It's from Simonds, J.L, Factors Affecting the Quality of Black-and-White Reflection Prints, Journal of Photographic Science, v. 11, 1963.
I've attached a print quality vs camera exposure curve for short and long toed films. It's from Simonds, J.L, Factors Affecting the Quality of Black-and-White Reflection Prints, Journal of Photographic Science, v. 11, 1963.
Stephen
Do you have an electronic version of this paper?
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