I was playing around with a 135 2.8 macro lens.. The macro lens was used because the smaller the item you photograph, the smaller the amount of depth of field you will have..
This shows a progression of closing (stopping down) the aperture. I think it was around f2.8 4, 5.6, 8, 11 and 16..
but it shows how you can take macro shots of something, using a smaller aperture, and get more in focus. Or if you are using a normal camera setup and just shooting bowls, it shows how the focus could be off by using the wrong fstop.
Each camera will be somewhat different, so you're gonna have to play wiht yours to see what it does..