Alan, for some reason I missed this earlier. Very interesting test. Just to clarify re Henry's tests, when there was pre-exposure he did find statistically significant fringe effects even with D-76. With no pre-exposure perhaps the problem is that he did not investigate longer agitation intervals than 1 minute, while your test started with 3 minute intervals. Or it may be he did not find any statistically significant edge effects. It also may be there is more density in the low density side of your negative than you thought. I think it makes some sense to expect a fringe effect of some kind even at base fog, but it would likely be very small so who knows.
Originally Posted by Alan Johnson
Henry used a variety of developers including Beutler and Rodinal and refers to these tests on p. 226. In fact his Rodinal tests were quite interesting. The developer produced more pronounced edge effects and higher granularity than D-76 1:1 with Pan-X and Tri-X, but not higher acutance.