That's the idea. I have never worked more than 3 images, almost always 2 at a time though I sometimes do selective region. The approach is most difficult on macro because of the dramatic image effects in small imaging misalignment-those error's cannot be corrected by linear methods-sometimes they work in your favor often they don't. Generally I have yet to get to a point were I can previsualize the effect accurately-hell its a shot in the dark when it comes to the details. I usually know that I will want to do an exclusion or a normal but the degree of focus change is usually a poke in the dark. Fun stuff, no?
This picture is an experiment. I'm just learning about sandwiches. This picture is composed from 6 separate shots, with focus on the far tip, center, and near tip of the large leaf for three of the pictures, and three other points up the stem for the other three. I used an action to select only those parts of each images that were near areas of detail, except for the bottom image which serves as the background. I then layered all the selections using normal method at 100%. -- Victor