A lamp assembly provides both instant light through use of an incandescent/halogen lamp source and an energy saving type light provided by a compact fluorescent lamp source. Both light sources are enclosed within a common envelope or outer bulb. The sensor member monitors light output from a central region of the CFL at a region spaced from the first and second ends in order to obtain an accurate representation of full light output from the CFL before shutting off or terminating power to the incandescent lamp source.