Ron, whatever story you like to create, but with EI 25 and developed in Dektol, how do you get 0.1 density above gross fog? You won't get that in daylight.

Your reference to gamma of 0.62 is incorrect. Gamma is the slope of the straight line portion of the curve, while ASA (and ISO) standard method for b&w negative films specify average gradient or g-bar. They are different quantities measured by different calculation on the sensitometric curve. On the other hand, speed measurement for print emulsion doesn't specify the contrast at all but calculate the speed by 10000 into the exposure (H) to yield the reflection density of 0.6.

Say an enlarging paper has ISO P500 speed, has short toe and reasonably straight line curve of g-bar of 2. This is typical of fast enlarging paper. That means we need H of 20 to get 0.6 density, and therefore H of 10 or a bit less to make barely discernible exposure above base and fog. Now, ISO b&w film speed can be estimated by dividing 0.8 by this exposure (H), which is around 0.1, even if we accept the g-bar of 2 instead of g-bar of 0.62. Most people expose paper negative at EI of 0.5 to 6 range, lower end of which is more common, because they are not necessarily exposing strictly for the shadow density, but because they consider the image is of sufficient quality if midtone and highlight are registered. So this accounts for the discrepancy between calculation and practice. However, a claim that the sufficient image quality can be obtained at EI25 is way off, based on both experience and calculation.

I have shared a lot of information about my emulsion as well as processing chemistry with many people on my web site and pure-silver. I have scans of my images made with my emulsion on the web as well. I've even given a free private emulsion-making workshop in Boston to several people.

In relation to sharing info with you, I've even told you how to desalt emulsions using phthalated gelatin precipitation method, how to manage fogging problems during optimal digestion problem, how to get maximum speed by making core-shell emulsions, etc. but I see you are having problems with the desalting and fog control, at least. I certainly won't bother to post every time I get some data.