I think you guys will get a better looking render if you change the initial model a bit. For the bulb, you actually want a two part piece, first a thin shell, and then the solid core. When rendering, if you set the shell to be glass and then the core as the light emitter, you'll get a much better representation of the actual lamp. It's especially obvious when you look at the sides of the bulb (relative to the camera), where in a real bulb, you'll have a small patch of transparent glass, as the emissive coating is on the inside of the glass. If the bulb is lit and putting out a realistic amount of light, of course, this will mostly (but not entirely) not be visible. It's a thin layer of glass, and it won't matter unless the bulb is going to be seen in closeup.