Correct, if you add a camera only admin, they only have the "Cameras" menu locale and they have access to view and/or export, do motion search, etc. They only get the Video and Analytics tabs, but no access to the settings or network or other tabs. As @MacuserJim mentioned, you could place the cameras in a separate Dashboard network, and then under Organization > Administrators create admins with full access to just the camera network and no org-wide access.