For all AF lenses, you stay in AF. When you take your test shots, we recommend the following:
1 - Rack the lens to one end. Take a shot. This is to make sure that the AF system triggered (and with any new adjustments).
2 - Then take 3-5 shots in sequence without changing the focus. Just trigger the AF with the shutter button as you do in normal shooting.
3 - When viewing the results, ignore the first shot. Then check the next 3-5 just to make sure that they are consistent. You do not want to base a test on an out-lier.
Use Manual Focus when you want to evaluate the viewfinder calibration and the entire manual focus light path in the camera.