Originally Posted by
DanK
Brian,
If I may, I think you are making this harder than it needs to be. You really don't need to deal with the technical stuff. If your goal is to use stacking to increase depth of field in macro work, then the bottom line is very simple: you need to take several photos with different planes of focus. You need enough of them so that across all of the photos, the entire range you want in focus is in focus in at least one of them. And you need to change the focus yourself. Ignore lighting for this purpose; lighting has nothing to do with it, and it will not create the differences in focus that you need. You can change the focus on numerous ways, but you almost never can do it with autofocus. Generally, you do it by changing the focus using the lens barrel, with the camera set to manual focus, or by moving the camera.
These changes of focus will generally be large enough that they will be readily apparent when you look at the images on the computer. You won't have people arguing about whether the focal plane is the same or not.
Dan