Got it. Thanks Andy. Only had a few minutes to test. The lens mount is the same (electronic contacts and all) as the Micro Four-Thirds mount that is on my Panasonic Lumix GH4 mirrorless camera. I slapped on an Panasonic Lumix 20mm f/1.7 II pancake lens and through the webUI you can set the iris (aperture) manually or have it on auto adjust the aperture. ON Auto, you can hear the aperture blades open and close if you cover the lens with your hand.
The autofocus is like the standard dahua cameras, essentially a fixed focus point.
The webUI has the same Near - Far slider bar or you can click on a portion of the image and it will autofocus, albeit, very, very slowly or click on the NEAR or FAR buttons for focus.
Hope do more tests as time allows to see which lens/focal length/aperture I would need at night to get a reasonable depth of field that is in focus.