A big challenge for all stacking programs is edges of flowers, leaves, stem. I generally see artifacts here, which I believe arise from combinations of different out-of-focus choices for background. By identifying the ‘deepest background’ with significant in-focus material and applying that to all areas for which no good focus exists, a sharp, realistic border could be created around areas of interest, and would approximate what an eye sees.
***Not sure how to deal with the fact that some OOF is in FRONT.
