One drawback with flash units is that you can’t accurately predict how the image is going to look until the flash has fired.
Although in these days of instant review it’s easy to adjust the units and shoot again, the advantage with continuous lights is you can see exactly what lighting effect you are getting as you adjust the lights. This also makes it easy to combine with existing, ambient light.
As for types, incandescent is the traditional source, but fluorescent and HMI are becoming increasingly popular in studios. The most efficient type of incandescent lighting is the tungsten-halogen lamp, which uses a coiled tungsten filament as in ordinary tungsten lights, but burning at a much higher temperature in halogen gas. As ...