T-Max in D76 (1:3) for greater sharpness (?)

[Ryuji]

The small amount of sulfite is that which is only a little more than is sufficient to form a Metol sulfonate from the oxidation product of Metol, according to data from the Theory of the Photographic Process. That same data showed that ascorbate, at pH below the point where ascorbate becomes an active developing agent, is equivalent to sulfite, mole for mole, for the purpose of counteracting the retardation by the oxidation products of Metol, although they work by different mechanisms. I wasn't expecting either it or the sulfite to be a preservative or a grain reducer. I think it's better to think of ways to avoid increasing grain, since the image is made of grains in any caase.

Disinhibition of metol development is one thing. But there are other requirements for practical developers. Preservative is an important component of a practical developer.

I think, though I didn't prove it, that the pH was still below that at which ascorbate is a developing agent, though it is an antioxidant. In other words, I don't think the synergism between Metol and ascorbate had much effect.

What's teh pH you refer to the point "at which ascorbate is a developing agent" because ascorbate is not a good developing agent by itself at any pH.

I have found from previous use that sulfite is not the grain reducer that some say it is. I probably should make it more clear when I am quoting popular belief that is not necessarilly my own. When I do a test of some hypothesis, I am prepared to accept the results whether or not they support the hypothesis, as I am sure you are as well.

You don't seem to understand what I am saying. Sulfite can decrease or increase the grain. You tested in conditions that sulfite doesn't have much effect on grain using D-76K. I looked at your original negative and prints. Many of developers you use (such as your classic PC carbonate) are same story. If you repeat the test at the same condition as before I'm sure you get the same results.

 

[gainer]

Ascorbate makes a pretty good lithographic developer at high pH with lots of bromide. I compared it once with hydroquinone and found it to have a somewhat higher inertia, but it had clean whites and very black blacks. I was quoting the conditions specified in the experiment described on p. 366-367 of Mees & James. They used pH = 8.7.

As I said, I was not testing for grain this time. I have suffered an attack of viral encephalitis in the meantime that messed with my memory access. All I can say is that it will take quite a bit more than 10X enlargement to show the difference in grain among D-23, the Metol-sulfite-borax developer, and the Metol-ascorbate-borax developer. After 12 hours in an open pitcher, the MCB had the same activity. There is a slight advantage in sharpness of fine detail to the ascorbate, but no one will ever see it at the viewing distance for proper perspective.

I agree that for many developers, it is important to have a preservative. I don't expect the ones I tested to live forever. I'm in my 80th year. The doctor said "You're oing to live to a hundred." I said "Oh, NO."

It appears that you are telling me why what I did cannot be done. Please tell me that is not so! If you are just telling me that it works, but not for any reasons I gave, that's OK.