Quote Originally Posted by Bill Burk View Post

You were on 10^-3? (I usually use 10^-2).
Tests were done at 10^2, 1/100. Earlier post is a typo, thanks for catching that.

Bill you should be able to test that. You don't need the EG&G line filters, just any ND to get both exposures somewhere on the step wedge to plot a slope.