Lighting Continuous Light Sources Continuous light sources include tungsten and quartz halogen bulbs. Their main advantage is that they allow you to predict exactly how the final image will appear. They generate a lot of heat though, making them unsuitable for delicate living subjects. They may require long shutter speeds, making them also inappropriate for moving subjects. Subject Brightness Range In general, digital cameras cannot record all the tones that the human eye can see. A typical bright sunny day might have a brightness range of well over eight stops, and the highlight may be several thousand times brighter than the shadow. A typical digital camera is only able to record successfully a range of around five stops, meaning that detail might be lost in either the shadows, highlights, or both. Several ways to modify the light are available, from diffusers and reflectors, to the use of electronic flash to "fill in" the shadows.