I have a further question. Some while back I get the Sony 30 mm Macro lens. As the 18-135 lens has 30 mm in its range, is it functioning as a macro? Are there other considerations I am missing.
Normally the dedicated Macro lens will let you get closer to your subject in order to get 1:1 magnification. If you check the "closest focusing distance" for both lenses, that will most likely be the case.