Hey Barbara - Dennis is right about the focusing rail since it appears that your Sony camera doesn’t have a focus bracketing function. Whenever I get lazy and don’t use auto bracketing, opting to select areas of focus myself, I almost invariably miss something. You could be more systematic about it and manually step your lens from the front area of focus to the back, which is what auto focus bracketing does. So that may help.
PMax and DMap are the two align and stack methods used to produce a final image. If you run Zerene you’ll see them under the Stack menu - stack DMap, stack PMax or Stack Both. I usually stack both and then use the DMap image as my base when retouching. Retouching can often get rid of the stack artifacts you see at the bottom of your image if you use one of your original images as your source for the pixel information. Retouching can also add details you want that might be missing or smudgy in a DMap by using the PMax stack as the source for your pixels.
There’s a long thread in the discussion area that might help you with future stacks - Focus Stacking
Let me know if I can help more.