You folks have given me a lot to think about. Thanks.
In the tests mentioned it sounds like I need a densitometer. Something that is not in the future for me.
Phil:
"I have used a zone board for HC110, PMK, ABC and pyrocatHD (its just one method!)"
I do not understand this. Do you mean that the Zone Board is one method of testing?
""This is exactly my point, what is significant?, and in relation to what?""
Well, perhaps I should have stated it differently. I would be surprised to see ANY change in the fb+f readings if care is taken to duplicate the development regime.
As far as what is significant, the fact that Picker says a reading ".08 to .10 above film base plus fog" is the proper film speed for a zone 1 negative tells me that a difference as high as .02 is fairly insignificant.
I still don't really see the problem, as you stated yourself that when you were using Tmx RS developer you saw little or no change in the readings.
That being said, your points regarding the changing of film etc. requiring a new slew of tests is a valid one. But wouldn't this still be the case with your method?
Enjoying the discussion....
As far as what is significant, the fact that Picker says a reading ".08 to .10 above film base plus fog" is the proper film speed for a zone 1 negative tells me that a difference as high as .02 is fairly insignificant
I disagree with this Rob, .02 might be insignificant if you have a density of .65, if you have a total density of .2 it is still 10% error. But remember since you are trying to match the Zone I (.1) to the clear part of the film your exposure is based only on .1 not .18 or .2 , so then .02 is 20% of your exposure. I have no idea how to express it better without showing you pictures, I hope this is clear.
With Tmx RS I saw no changes for "normal" development, but I did see great changes for expanded developing, b+f went from .09 to as much as .14
if I was using the max black test I would have an error of 50%.
As to my film testing, since it does not rely on the paper to make a judgement you are correct, I have to make a test for every film/developer combo, but the difference is that since I know the exposure scale of my paper I fit all my film developing to fit the paper's curve which results in not having to make any more paper tests. For example I know that if I have a negative that has a density range of 1.28 that it will print well using developer solution #2 exposed at 500 units of light in my Nu arc ( I am talking about pt/pd here, since it has been years since I have done silver printing) I dont have to do test strip, etc. I just put the paper under the light, dial 500 and I have a print that has all the useful information I need, from there I concentrate on contrast changes etc, but there have been times when I expose the print and it comes out perfect on the first try, and this is the goal of appropriate testing, to get as close as you can to a perfect exposure without much waste, this is specially relevant with pt/pd, which is not cheap, a failing I find enlarging paper has, if you had to pay $3 per sheet of paper, I bet you would have learned how to control your materials better by now.
But I digress, look my point is, that if you plan to use the paper as a tool to judge the negative development, then the paper should be a fixed constant that is capable of "absorbing" small variations, and the max black test does not do this.
I hesitated to write this down in the previous response in fear of sounding condescending, but lets "walk" through an example.
Suppose you try a new film/developer combo, and you have made your standard printing time based on a Zone V neg. From experience I know that grades 1, 2 and 3 will have very close exposures, and this is important to be able to judge film development. So then you develop your film, you put in the enlarger and you make your test print with paper grade 2 at the Zone V printing time. The resulting print is too contrasty, at this moment you have already gathered two important pieces of information. You now know you either developed the film too much, or that your negative density range fits better a paper of lower grade. You then change the paper to grade 1 and expose for the same Zone V time, your print comes out better, with good highlights and still nice dark tones. At this point you have two choices, you can keep the same development time and just print on paper grade 1 or reduce the development time to print on grade two. Notice however that I said this is a new film/developer combo, yet you still are using the paper printing times of your old combo, you dont need to make a new Zone V test for the new combination since small variations wont make a difference when exposing the paper. Furthermore, depending on how light was the print on the first exposure you can guesstime how much time to reduce the film development.
All of this is not available in the max black test, if you expose your new combo to a new max black test, (the old one does not work anymore because of the b+f thing). you still dont know if the information given on the print is due to too much development, what happens if your film has a short toe and zone I is fine but then the following zones jump up?
I am almost sure that this has happened to you, you make your max black test and your print does not look right, you then change paper contrast (make a new max black test) and still it does not look right, you then wonder if all that was required in the first test was more/less exposure, or if the second test needs more/less exposure and you still have no information about the negative development itself. You then proceed to make test strip on the paper, I wonder, why make the max black test if you still have to make test strips?
To compound on all these objections, what if your Zone I is .15 or .19 over b+f? Rarely have I seen a film test where the film comes at exactly .1 over b+f, So far we have assumed that you are getting a perfect result, but this is not the case in real life, at least not in my expereince.
IMO this is no way to work, or at least I could not work like this. I just cant see how the max black test can give any useful information other than how to make a nice black print.
Mark: For a description of the Zone board, see Gordon Hutchings' _The Book of Pyro_.
It's a simple and ingenious concept. The idea is that you have a light colored board, maybe 6 or 8 feet long, with a lamp at the top aimed downward. There are labels from I to X with arrows running along the long side. Place Zone I somewhere at the greatest distance from the lamp, and then use a spot meter to find where the other zones are, and label them as such (II, III, etc.). Photograph it, take notes on exposure, and you can use it for speed and development tests and to plot film curves.
You don't even need to build anything to use it. If you've got a light stand or a convenient way of mounting a lamp in this manner, you could use a light-colored wall and Post-It notes with the zone values written in thick marker as a Zone board.
Things to be careful of with this approach--don't use a wide lens for the test, or your results will be confused by falloff of illumination at the edge of the image circle. The camera should be far enough away so that bellows factor doesn't enter in if possible. Also use a bright enough lamp so that reciprocity isn't a factor for the test.
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