I've been using the expodev software for a while on and off and get some great results but keep coming back to a puzzle.
I understand for the filter factors, you enter, for example, "8" for a 3-stop filter, i.e. the number of times the light is reduced. That's OK for colour temp. filters etc but what about when you're using a red filter to bump up the contrast of a sky? Do you need to alter your zone placements in line with the filter used or just stick to the placements as seen and use the basic factor?
I haven't used B&W contrast filters much as most of my pictures have been inside so this is slightly new territory with landscapes...