Thanks, Rob, I'll remember that for my next macro session. After I completed the stacking process, I did wonder if I should have used the large aperture shots, because some haziness is visible in some areas that were defocused in the large aperture shots. On the other hand, I sort of like the effect in this case, because it sharpens the blooms while enhancing the feathery appearance in the downy areas. This is particularly noticable in the corners of the Set A image, in the "vignette" areas I mentioned earlier. Thanks for straightening me out about the proper use of stacking... the process really is simple, even if the name does make it sound intimidating.