Not quite that simple, unless I have been missing a trick. But first, be warned - DAZ cameras do not act like real cameras so far as f-stop, etc. go.
What I do is create (at least) two cameras - one to use for the render (I generally call this SceneCam, with DoF, etc.,) and the other(s) to assist in posing and positioning.
In the Camera/Lights tab (selecting Camera) I ensure that I have the SceneCam selected as active object and another camera active in view port. I adjust scene so that I have a clear view from SceneCam to where I want the central focal point be. I then turn on DoF for the SceneCam and turn the DoF planes/indicators under Scene View (sorry, can’t recall actual titles) to red so they stand out. Focal length and f-stop are then adjusted to suit what I have planned.